1、 STD-ITU-T RECMN X.77-ENGL 1997 S 4862.593 Ob43152 TTO m INTERNATIONAL TELECOMMUNICATION UNION ITU=T TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU x.77 (O 8/9 7) SERIES X: DATA NETWORKS AND OPEN SYSTEM COM M U N i CATI O N Public data networks - Transmission, signalling and switching Interworking
2、between PSPDNs via B-ISDN ITU-T Recommendation X.77 (Previously CCITT Recommendation) ITU-T X-SERIES RECOMMENDATIONS DATA NETWORKS AND OPEN SYSTEM COMMUNICATION PUBLIC DATA NETWORKS X. 1-X.199 Services and facilities Interfaces X.20-X.49 X. l-X. 19 Network aspects X.90-X. 149 X. 150-X. 179 X.180-X.1
3、99 Maintenance Administrative arrangements OPEN SYSTEM INTERCONNECTION X.200-X.299 Model and notation X.200-X.209 Service definitions X.210-X.219 Connection-mode protocol specifications X.220-X.229 Connectionless-mode protocol specifications X.230-X.239 PICS proformas X.240-X.259 Protocol Identifica
4、tion X.260-X.269 Security Protocols X.270-X.279 Layer Managed Objects X.280-X.289 Conformance testing X.290-X.299 INTERWORKING BETWEEN NETWORKS x.300-x.399 General X.300-X.349 Satellite data transmission systems X.350-X.399 MESSAGE HANDLING SYSTEMS X.400-X.499 DIRECTORY X.500-X. 599 OS1 NETWORKING A
5、ND SYSTEM ASPECTS X.600-X.699 Networking X.600-X.629 Efficiency X.630-X.649 Naming, Addressing and Registration X.650-X.679 Abstract Syntax Notation One (ASN. 1) X.680-X.699 X.700-X.799 Systems Management framework and architecture X.700-X.709 Management Communication Service and Protocol X.7 10-X.7
6、 1 9 Structure of Management Information X.720-X.729 1 Management functions X.730-X.799 SECURITY X. 800-X. 849 OS1 APPLICATIONS X.850-X.899 Commitment, Concurrency and Recovery X.850-X.859 Transaction processing X.860-X.879 Remote operations X.880-X. 899 OPEN DISTRIBUTED PROCESSING X.900-X.999 OS1 M
7、ANAGEMENT I For further details, please refer to ITU-T List of Recommendations. STD-ITU-T RECMN X.77-ENGL I1997 W 486259% Ob43154 873 W ITU-T RECOMMENDATION X.77 INTERWORKING BETWEEN PSPDNS VIA B-ISDN Summary This Recommendation defines the procedures for interworking case of concatenation of PSDTSs
8、 via B-ISDN. It includes reference configurations, protocol stacks and detailed signalling procedures. The Recommendation may be used in the case where packet-switched links between networks providing PSDTS services are transferred over B-ISDN networks as backbone networks. Source ITU-T Recommendati
9、on X.77 was prepared by ITU-T Study Group 7 (1997-2000) and was approved under the WTSC Resolution No. 1 procedure on the 9th of August 1997. Recommendation X.77 (08/97) 1 FOREWORD ITU (International Telecommunication Union) is the United Nations Specialized Agency in the field of telecommuni- catio
10、ns. 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 standardizing telecommunications on a worldwide basis. The World Telecommun
11、ication 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 the Members of the ITU-T is covered by the procedure laid down in WTSC
12、 Resolution No. 1. In some areas of information technology which fall within IT-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 admini
13、stration 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
14、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 ITU had not received notice of intellectual property, protected by patents, which may be required
15、 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 1998 All rights reserved. No part of this publication may be reproduced or utilized in any form or by a
16、ny means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the ITU. 11 Recommendation X.77 (08197) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 CONTENTS Scope of the Recommendation . References Terms and definitions . Abbreviations . Conventions . Reference conf
17、igurations . Case where B-ISDN provides PVC 6.1 6.2 Case where B-ISDN provides SVC 7.1 Peak cell rate . 7.2 Service quality Addressing and routing aspects Service parameters and service quality . Physical layer . ATM layer ATM adaptation layer 11.2 C-plane LAPB control layer 13.1 General . 13.2 Outg
18、oing X.75 call 13.3 Incoming X.75 call . 13.4 ATM switched virtual channel connection clearing . 13.6 Handling of Error condition 14.1 General 14.2 Physical interface 14.3 Mapping of signalling information and procedures between the X.75 interface and the SBTB reference point 14.5 Maintenance 11.1 U
19、-plane . Signalling procedures . 13.5 Restart procedures ATM-Adaptor functionalities 14.4 Synchronization Annex A . X.77 example message flow diagrams X.77 call Set-up message flow sequences . X.77 call clearing message flow sequences Annex B - The mapping Q.2931 cause information element identifier
20、 field to X.75 cause . A.l A.2 A.3 X.77 restart message flow sequences . Recommendation X.77 (08/97) - Page 1 1 2 2 3 3 3 4 4 4 4 5 5 6 6 6 8 8 9 9 9 10 10 11 11 11 11 13 13 13 13 13 13 14 15 20 . 111 Recommendation X.77 INTERWORKING BETWEEN PSPDNS VIA B-ISDN (Geneva, 199 7) 1 Scope of the Recommend
21、ation This Recommendation defines the procedures for interworking case of concatenation of PSDTSs via B-ISDN. It includes reference configurations, protocol stacks and detailed signalling procedures. 2 References The following ITU-T Recommendations and other references contain provisions which, thro
22、ugh 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 therefore encouraged to investigate the possibility of apply
23、ing the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. - - ITU-T Recommendation E. 164 (1 997), The international public telecommunication numbering plan. ITU-T Recommendation E.166 (1996), Num
24、beringplan interworking for the E.164 andX.121 numberingplans. ITU-T Recommendation I. 150 (1999, B-ISDN asynchronous transfer modefunctional characteristics. ITU-T Recommendation 1.2 1 1 (1 993), B-ISDN service aspects. ITU-T Recommendation 1.36 1 (1 995), B-ISDN ATM layer specification. ITU-T Reco
25、mmendation 1.363 (1 993), B-ISDN ATMAdaptation Layer (AAL) speci3cation. ITU-T Recommendation 1.365.1 (1993), B-ISDN ATM adaptation layer sublayers: Frame relaying service specific convergence sublayer (FR-SSCS). ITU-T Recommendation 1.37 1 (1 996), Trafic control and congestion control in B-ISDN. I
26、TU-T Recommendation 1.413 (1993), B-ISDN user-network interface. ITU-T Recommendation 1.430 (1 999, Basic user-network interface - Layer I spec9cation. ITU-T Recommendation 1.43 1 (1 993), Primary rate user-network interface - Layer 1 specification. ITU-T Recommendation 1.432 (1 993), B-ISDN user-ne
27、twork interface - Physical layer specification. ITU-T draft Recommendation 1.5 05, Identzjication and selection of interworkingfunction. - - - - - - - - - - - - ITU-T Recommendation IS80 (1995), General arrangements for interworking between B-ISDN and 64 kbit/s based ISDN. - ITU-T Recommendation Q.2
28、110 (1994), B-ISDN ATM adaptation layer - Service Specific Connection Oriented Protocol SSCOP). - ITU-T Recommendation 4.2130 (1994), B-ISDN signalling ATM adaptation layer - Service Specijc Coordination Function for support of signalling at the User-Network Interface (SSCF at Wo. - ITU-T Recommenda
29、tion 4.2931 (1995), Digital Subscriber Signalling System No. 2 (DSS 2) - User-Network Interface UNI) layer 3 specification for basic call/connection control. ITU-T Recommendation X.l (1996), International user classes of service in, and categories of access io, public data networks and Integrated Se
30、rvices Digital Networks (ISDNs). - Recommendation X.77 (08/97) 1 - STDmITU-T RECMN X.77-ENGL II997 M 4862591 0643b58 419 I - ITU-T Recommendation X.25 (1996), Interface between Data Terminal Equipment (DTE) and Data Circuit-terminating Equipment (DCE) for terminals operating in the packet mode and c
31、onnected to public data networks by dedicated circuit. - ITU-T Recommendation X.31(1995), Support ofpacket mode terminal equipment by an ISDN. - ITU-T Recommendation X.32 (1996), Intedace between Data Terminal Equipment (DTE) and Data Circuit-terminating Equipment (DCE) for terminals operating in th
32、e 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-switched public data network. ITU-T Recommendation X.75 (1996), Packet-switched signalling system between public networks providing dat
33、a transmission services. ITU-T Recommendation X.121(1996), Internationai numberingplan for public data networks. ITU-T Recommendation X.122 (1 996), Numbering plan interworking for E. 164 andX 121 numberingplans. ITU-T Recommendation X.213 (1995) I ISODEC 8348:1996, Information technology - Open Sys
34、tems Interconnec- tion -Network service definition. ITU-T Recommendation 1.365.4 (1 996), B-ISDN ATM adaptation layer. sublayers: Service specific convergence sublayer for HDLC applications. - - - - - 3 Terms and definitions This Recommendation defines the following terms. 3.1 DL-FRAME SSCF: The Ser
35、vice Specific Convergence Function for HDLC Applications. Detailed description for DL-FRAME SSCF is shown in Recommendation 1.365.4. 4 Abbreviations This Recommendation uses the following abbreviations: AAL ATM AU B-ET B-ISDN B-NT B-TA BCOB CH CPCS CPCS-CI CPCS-LP c PC s -uu DNIC DTE ISDN IWF NT ATM
36、 Adaptation Layer Asynchronous Transfer Mode Access Unit Exchange Terminal for Broadband ISDN Broadband ISDN Network Termination for Broadband ISDN Terminal Adaptor for Broadband ISDN Broadband Connection Oriented Bearer class Cell Handler Common Part Convergence Sublayer CPCS-Congestion Indication
37、CPCS-Loss Priority CPCS-User-to-User indication Data Network Identification Code Data Terminal Equipment Integrated Services Digital Network Interworking Function Network Termination 2 Recommendation X.77 (08197) STD-ITU-T RECMN X.77-ENGL 1997 4862591 Ob43159 355 PH Packet Handler PMBS Packet Mode B
38、earer Service PSDTS Packet-Switched Data Transmission Services PSPDN Packet-Switched Public Data Network PVC Permanent Virtual Circuit QOS Quality of Service SSCF Service Specific Convergence Function STE Signalling Terminal svc Switched Virtual Call TA Terminal Adaptor TE Terminal Equipment VCI Vir
39、tual Channel Identifier VPCI Virtual Path Connection Identifier 5 Conventions No particular conventions are included. 6 Reference configurations There are two cases in terms of the connection establishment method through the B-ISDN network (see Figure 6.1): - the case where B-ISDN connections are Pe
40、rmanent virtual channel (PVC); - the case where B-ISDN connections are Switched virtual channel (SVC). In this configuration, an X.77 signalling terminal (X.77-STE) with X.75 and ATM capabilities is equivalent to a combination consisting of an X.75 Signalling Terminal (STE) and an ATM-Adaptor with A
41、TM capabilities (for ATM capabilities; see clause 14). Interfaces between X.77-STE/ATM-Adaptor and the B-ISDN are UNI of the B-ISDN. An X.75 datalink connection shall be associated with one ATM virtual channel. 6.1 In the case where ATM connection is PVC, the protocol stack is shown in Figure 6-2. C
42、ase where B-ISDN provides PVC Either ATM-Adaptor or X.77-STE should support AAL type 5 Common part function and DL-FRAME SSCF (see 11.1.1) to convey X.75 fiames. NOTE - Use of AAL type 1 instead of AAL type 5 should not be precluded. In the case where AAL type 5 is used, AAL type 5 message mode serv
43、ice will be available. The functionality of the DL-FRAME SSCF only provides for the mapping of the equivalent primitives of AAL to CPCS and vice versa. In this case, the ATM connection shall be established by procedures beyond the scope of this Recommendation. Recommendation X.77 (OW97 3 PSPDNI ISDN
44、-VC PSPDNI ISDN -VC PSPDNI I IS DN-VC ATM-Adaptor PSPDN I ISDN-VC “;i T0726550-9WdOl NOTE - SVC case of using ATM-Adaptor is for further study Figure 6-1K.77 - Reference configuration of interworking between networks providing PSDTSs via B-ISDNs 6.2 6.2.1 U-plane See 6.1. 6.2.2 C-plane C-plane proto
45、col stack is shown in Figure 6-3. ATM connection shall be established by the procedures specified in clause 13. Case where B-ISDN provides SVC 7 Service parameters and service quality 7.1 Peak cell rate The Peak Cell Rate in the Source Traffic Descriptor specifies an upper bound on the traffic that
46、can be applied on an ATM connection. Enforcement of this bound by the UPC/NPC allows the network operator to allocate sufficient resources to ensure that the performance objectives (e.g. for Cell Loss Ratio) can be achieved (see 2.4.M.371). 7.2 Service quality The QOS level for Peak Cell Rate may be
47、 delivered within a certain probability. NOTE - Other parameters are for further study. 4 Recommendation X.77 (08/97) STDDITU-T RECMN X-77-ENGL 1997 I 48b2591 0643363 TO3 S x.75 x.75 packet layer packet layer LAPB control , layer x.75 linklayer DL-FRAME , SSCF AALS-CP 4 b. ATM 4 b PHY PHY 4 b X.77-S
48、TE X.77-STE x.75 x.75 packet layer packet layer LAP6 control layer x.75 DL-FRAME link layer SSCF AAL5-CP ATM PHY PHY (Note) T0726560-96/d02 NOTE - X.75 or some equivalent internal network protocols.This figure shows the protocol stack where X.75 is used here. Figure 6-2X.77 - Packet mode interworkin
49、g based on reference configuration of concatenation of 64 kbit/s based ISDNs via B-ISDN (-plane) 8 Addressing and routing aspects One E. 164 number of the B-ISDN is associated with one X.77-STEK75-STE + ATM-Adaptor. The 4.2931 SETUP message, when used, contains the request for class C bearer service. The SETUP message also contains the B-ISDN address of the X.77-STEATM-Adaptor of the remote PSDTS network. NOTE - Request of class A bearer service in the SETUP message should not be precluded. X.75 call request packet contains the X.121 or E.164 address
