1、STD-ITU-T RECMN X-?B-ENGL 1999 4862591 0664330 995 INTERNATIONAL TELECOMMUNICATION UNION ITU-T TELECOMMUNICATION STAN DAR DIZATION SECTOR OF ITU X.78 (06/99) SERIES X: DATA NETWORKS AND OPEN SYSTEM COMMUNICATIONS Public data networks - Transmission, signalling and switching Interworking procedures b
2、etween networks providing frame relay data transmission services via B4SDN ITU-T Recommendation X.78 (Previously CCITT Recommendation) ITU-T X-SERIES RECOMMENDATIONS DATA NETWORKS AND OPEN SYSTEM COMMUNICATIONS UBLIC DATA NETWORKS Services and facilities X.1-X. 19 X.20-X.49 nterfaces Network aspects
3、 Maintenance Administrative arrangements )PEN SYSTEMS INTERCONNECTION Model and notation Service definitions Connection-mode protocol specifications Connectionless-mode protocol specifications PICS proformas Protocol Identification Security Protocols Layer Managed Objects Conformance testing :NTERWO
4、RKING BETWEEN NETWORKS General Satellite data transmission systems MESSAGE HANDLING SYSTEMS DIRECTORY OS1 NETWORKING AND SYSTEM ASPECTS Networking Efficiency Quality of service Naming, Addressing and Registration Abstract Syntax Notation One (ASN.l) OS1 MANAGEMENT Systems Management framework and ar
5、chitecture Management Communication Service and Protocol Structure of Management Information Management functions and ODMA functions SECURITY OS1 APPLICATIONS Commitment, Concurrency and Recovery Transaction processing Remote operations OPEN DISTRIBUTED PROCESSING X.90-X.149 X.150-X.179 X. 180-X. 19
6、9 X .200-X .209 X.2 1 0-X.2 19 X.220-X.229 X.230-X.239 X.240-X.259 X.260-X.269 X.270-X.279 X.280-X.289 X.290-X.299 X.300-X.349 x.350-x.399 X.400-X.499 x.500-x.599 X.600-X.629 X.630-X.639 X. 640-X. 649 X.650-X.679 X.680-X.699 X.700-X.709 X.710-X.719 X.720-X.729 x.730-x.799 X. 800-X.849 X.850-X.859 X.
7、860-X.879 X.880-X.899 X.900-X.999 For further details, please refer to TU-T List of Recommendations. ITU-T RECOMMENDATION Xe78 INTERWORKING PROCEDURES BETWEEN NETWORKS PROVIDING FRAME RELAY DATA TRANSMISSION SERVICES VIA B-ISDN Summary This Recommendation defines the procedures for interworking case
8、 of concatenation of networks providing FRDTS via B-ISDN. It includes reference configurations, protocol stacks and detailed signalling procedures. This Recommen- dation may be used in the case where frame relay links between networks providing FRDTS services are transferred over B-ISDN networks as
9、backbone networks. Interworking scenario used in this Recommendation is Network interworking scenario as specified in Recommendation 1.555, and port access method of interworking as specified in . the X.300-series Recommendations. Source ITU-T Recommendation X.78 was prepared by ITU-T Study Group 7
10、(1997-2000) and was approved under the WTSC Resolution No. 1 procedure on the 18th of June 1999. Recommendation X.78 (06/99) 1 STDmITU-T RECMN X.7B-ENGL 1999 4b2591i Ob64333 bT4 m FOREWORD ITU (International Telecommunication Union) is the United Nations Specialized Agency in the field of telecommun
11、i- cations. 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 Te
12、lecommunication 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
13、 in WTSC Resolution 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 term recognized operating agency (ROA) includes any individual, company, corporation or
14、 governmental organization that operates a public correspondence service. The terms Administration, 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
15、this Recommendation may involve the use of a claimed Intellectual Property Right. The ITU takes no position 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 t
16、he date of approval of this Recommendation, the ITU had not received notice of intellectual property, protected 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
17、to consult the TSB patent database. O ITU 1999 All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the ITU. 11 Recommendation X.78 (06/99) . STDm
18、ITU-T RECMN X.78-ENGL 1999 48b259L Ob64334 530 1 2 3 4 5 6 7 8 9 10 11 12 13 CONTENTS Scope References Terms and Definitions Abbreviations Conventions Reference Configurations . Case where B-ISDN provides PVC . Case where B-ISDN provides SVC . Service parameters and Service quality 7.1 Peak cell rat
19、e . 7.2 Service quality . Addressing and routing aspects 6.1 6.2 Physical layer ATM layer ATM Adaptation layer 11.2 C-plane 11.1 U-plane Signalling procedures . 12.2 Outgoing X.76 Call . 12.3 Incoming X.76 Call . ATM Switched Virtual Channel Connection Clearing 12.1 General : . 12.4 12.5 Restart Pro
20、cedures . 12.6 Handling of Error condition 13.1 General 13.3 Mapping of signalling information and procedures between the X.76 interface and the SB/TB 13.4 Synchronization . 13.5 Maintenance ATM-adaptor functionalities 13.2 Physical interface reference point . Annex A . X.78 example message flow dia
21、grams X.78 call setup message flow sequences . A.l A.2 A.3 X.78 call releasing message flow sequences . X.78 restart message flow sequences Annex B - The mapping of 4.2931 Cause information element identifier field to X.76 cause . Recommendation X.78 (06199) Page 1 1 2 2 3 3 3 4 5 5 5 6 6 6 6 6 6 6
22、6 7 7 8 8 8 9 9 10 10 10 10 10 10 12 12 16 iii Recommendation X.78 INTERWORKING PROCEDURES BETWEEN NETWORKS PROVIDING FRAME RELAY DATA TRANSMISSION SERVICES VIA B-ISDN (Geneva, I999) 1 Scope This Recommendation defines the procedures for interworking case of concatenation of networks providing FRDTS
23、 via B-ISDN. It includes reference configurations, protocol stacks and detailed signalling procedures. Interworking scenario used in this Recommendation is Network interworking scenario as specified in Recommendation 1.555, and port access method of interworking as specified in the X.300-series Reco
24、mmendations. 2 References The following ITU-T Recommendations 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 subje
25、ct to revision; all users of this Recommendation are therefore encouraged to investigate the possibility of applying 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. 1
26、64 (1997), The international public telecommunication numbering plan. CCITT Recommendation G.702 (1988), Digital hierarchy bit rares. ITU-T Recommendation G.804 (1998), ATM cell mapping into Plesiochronous Digiraf Hierarchy (PDH). ITU-T Recommendation 1.361 (1999), B-ISDN ATM layer specification. IT
27、U-T Recommendation 1.362 (1993 - withdrawn in 1997), B-ISDN ATM adaptation layer (AAL) functional description. ITU-T Recommendation 1.363 (1 993), B-ISDN ATM adaptation layer (AAL) specification. ITU-T Recommendation 1.365.1 (1 993), Frame Relaying Service Specific Convergence Sublayer (FR-SSCS). IT
28、U-T Recommendation 1.371 (1996), Trafic control and congestion control in B-ISDN. ITU-T Recommendation 1.41 3 (1993), B-ISDN user-network interface. ITU-T Recommendation 1.430 (1993, Basic user-network interface - Layer I specification. ITU-T Recommendation 1.432, B-ISDN user-network inte$ace - Phys
29、ical layer specifcation. ITU-T Recommendation 1.555 (1997), Frame relaying bearer service interworking. ITU-T Recommendation 1.610 (1999), B-ISDN operation and maintenance principles andfunctions. ITU-T Recommendation Q.2110 (1994), B-ISDN ATM adaptation layer - Sewice specific connection oriented p
30、rotocol (SSCOP). Recommendation X.78 (06/99) 1 ITU-T Recommendation Q.2130 (1994), B-ISDN signalling ATM adaptation layer - Service specific coordination function for support of signalling at the user-network integace (SSCF at UNI). XTU-T Recommendation 4.2931 (1995). Digital Subscriber Signalling S
31、ystem No. 2 - User-Network Inte$ace (UNI) layer 3 specification for basic caluconnection control. ITU-T Recommendation X.76 (1995). Network-to-network interface between public data networks providing theframe relay datu transmission service. ITU-T Recommendation X.76 (1995)/Amendment 1 (1997), Netwo
32、rk-to-nefwork interface between public datu networks providing the frame relay data transmission service - Amd. 1: Switched Virtual Circuits. Terms and Definitions This Recommendation defines the following term: 3.1 between AAL and Link Access Procedure for Frame mode bearer service (LAPF) (see Reco
33、mmendation 1.365.1). Frame Relay Service Specific Convergence Sublayer: FR SSCS is used at the TE and AU to interworking 4 Abbreviations This Recommendation uses the following abbreviations: AAL ATM AU B-ISDN BCOB CPCS FRDTS FFDN ISDN PVC QOS sscs STE svc VCI VPCI 2 ATM Adaptation Layer Asynchronous
34、 Transfer Mode Access Unit Broadband ISDN Broadband Connection Oriented Bearer class Common Part Convergence Sublayer Frame Relay Data Transmission Services Frame Relay Public Data Network Integrated Services Digital Network Permanent Virtual Circuit Quality of Service Service Specific Convergence S
35、ublayer Signalling Terminal Switched Virtual Circuit Virtual Channel Identifier Virtual Path Connection Identifier Recommendation X.78 (06/99) STD-ITU-T RECMN X.78-ENGL L999 W 4862591i 0664337 24T W 5 Conventions No particular conventions are included. 6 Reference Configurations There are two cases
36、in terms of the connection establishment method through the B-ISDN network (see Figure 6-1). - - The case where B-ISDN connections are PVC (Permanent virtual channel). The case where B-ISDN connections are SVC (Switched virtual channel). In this configuration. an X.78 signalling terminal (X.78-STE)
37、with X.76 and ATM capabilities is equivalent to a combination consisting of an X.76 signalling terminal (STE) and a ATM-adaptor with ATM capabilities. (For ATM adaptor functionalities, see clause 13.) Interfaces between X.78-STEATM-adaptor and the B-ISDN are UNI of the B-ISDN (see Recommendation 1.4
38、1 3). An X.76 data link connection shall be associated with one ATM virtual channel. FRPDNI ISDN-FRDTS X.78-STE FRPDNI ISDN-FRDTS X.78-STE 8-ISDN FRPDNI FRPDNI networks ISDN-FRDTS ISDN-FRDTS FRPDNI ISDN-FRDTS -/ FRPDNI ISDN-FRDTS ATM-adaptor NOTE - SVC case of using ATM-Adaptor is for further study.
39、 FRPDN/ ISDN- FR DTS X.78-STE FRPDNI q-adapFcq1 ISDN-FRDTS T0731890-99/d01 Figure 6-1B.78 - Reference configuration of iterworking between networks providing FRDTS via B-ISDNs 6.1 In the case where ATM connection is PVC, the protocol stack is shown in Figure 6-2. Case where B-ISDN provides PVC 3 Rec
40、ommendation X.78 (06/99) Either ATM-adaptor or X.78-STE should support AAL type 5 Common part function and FR-SSCS to convey X.76 frames. X.76 signalling X.76 Link layer PHY NOTE - Use of AAL type 1 instead of AAL type 5 should not be precluded. X.76 4 signalling FR-SSCS 4 b FR-SSCS X.76 link layer
41、AALSCP 4 b AALSCP ATM 4 b ATM PHY PHY 4 F PHY In the case where AAL type 5 is used, AAL type 5 message mode service will be available. The functionality of FR-SSCS only provides for the mapping of the equivalent primitives of AAL to CPCS and vice versa. In this case, the ATM connection shall be esta
42、blished by procedures beyond the scope of this Recommendation. X.78-STE X.78-STE NOTE - X.76 or some equivalent internal network protocols. Figure 6-2K.78 - Frame relay interworking based on reference configuration of concatenation of networks providing FRDTS via B-ISDN where B-ISDN provides PVCs (U
43、-piane) 6.2 Case where B-ISDN provides SVC 6.2.1 U-plane See 6.1. 6.2.2 C-plane C-plane protocol stack is shown in Figure 6-3. ATM connection shall be established by the procedures specified in clause 12. 4 Recommendation X.78 (06/99) STD-ITU-T RECMN X.7B-ENGL 3999 4862593 O664339 012 (2.2931 SSCF S
44、SCOP AALSCP ATM X.78-STE X.78-STE + b (2.2931 + b SSCF c b SSCOP 4 b AALSCP 4 b ATM C$TE I- (Note) (Note) X.76 signalling 4 b C-plane X.76 signalling U-plane PHY ATM - ATM PHY PHY 4 b PHY PHY PHY FR-SSCS FR-SSCS x.76 Link layer link layer AALSCP AALSCP (core) (core) NOTE - X.76 or some equivalent in
45、ternal network protocols. Figure 6-3K.78 - Frame relay interworking based on reference configuration of concatenation of networks providing FRDTS via B-ISDN where B-ISDN provides SVCs (U-plane and C-plane) 7 Service parameters and Service quality 7.1 Peak cell rate The Peak Cell Rate in the Source T
46、raffic Descriptor specifies an upper bound on the traffic that 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 2.4.14.
47、371.) 7.2 Service quality The QoS levei for Peak Cell Rate may be delivered within a certain probability. NOTE - Other parameters are for further study. Recommendation X.78 (06/99) 5 8 Addressing and routing aspects One E.164 number of the B-ISDN is associated with one X.78-STEK76-STE + ATM adaptor.
48、 The Q.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.78-STE/ATM adaptor of the remote FRDTS network. NOTE - Request of class A bearer service in the SETUP message should not be precluded. X.76 call request
49、packet contains the address of the destination terminal. X.78-STE/ATM-adaptor can establish multiple ATM connections to some destinations. X.78-STEIATM-adaptor using multiple ATM virtual paths and virtual channels. 9 Physical layer Physical medium characteristics of UNI are defined in Recommendation 1.432. ATM cell mapping into Plesiochronous Digital Hierarchy (PDH) defined in Recommendation G.702 is also possible. See Recommendation G.804. 10 ATMlayer See Recommendation 1.361 for ATM layer specification. 11 ATM Adaptation layer 11.1 U-plane Type 5 of the AAL f
