1、INTERNATIONAL TELECOMMUNICATION UNION ITU-T TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU X.634 (I 0/96) SERIES X: DATA NETWORKS AND OPEN SYSTEM COMMUNICATION OS1 networking and system aspects - Efficiency Information technology - Open Systems Interconnection - Transport Fast Byte Protocol ITU-T R
2、ecommendation X.634 (Previously ”CCITT Recommendation”) ITU-T X-SERIES RECOMMENDATIONS DATA NETWORKS AND OPEN SYSTEM COMMUNICATION PUBLIC DATA NETWORKS Services and facilities Interfaces Transmission, signalling and switching Network aspects Maintenance X. 1-X. 199 X.l-X. 19 X.20-X.49 X.50-X.89 X.90
3、-X.149 X. 150-X. 179 Administrative arrangements X. 180-X. 199 OPEN SYSTEM INTERCONNECTION Model and notation Service definitions Connection-mode protocol specifications Connectionless-mode protocol specification PICS profomas X.200-X.299 X.200-X.209 X.210-X.219 X.220-X.229 X.230-X.239 X.240-X.259 P
4、rotocol Identification X.260-X.269 Security Protocols Layer Managed Objects Conformance testing General Satellite data transmission systems MESSAGE HANDLING SYSTEMS INTERWORKING BETWEEN NETWORKS X.270-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 DIRECTORY X.500-X.599
5、 Networking X.600-X.629 - Efficiency Naming, Addressing and Registration Abstract Syntax Notation One (ASN.l) Systems Management framework and architecture OS1 MANAGEMENT X.650-X.679 X.680-X.699 X.700-X.799 X.700-X.709 X.710-X.7 19 Management Communication Service and Protocol I Structure of Managem
6、ent Information , Management functions SECURITY OS1 APPLICATIONS Commitment, Concurrency and Recovery Transaction processing Remote operations OPEN DISTRIBUTED PROCESSING 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 Il For further details, please re
7、fer to ITW-T List of Recommendations. FOREWORD ITU (International Telecommunication Union) is the United Nations Specialized Agency in the field of telecommunications. The IT Telecommunication Standardization Sector (ITU-T) is a permanent organ of the ITU. Some 179 member countries, 84 telecom opera
8、ting entities, 145 scientific and industrial organizations and 38 international organizations participate in ITU-T which is the body which sets world telecommunications standards (Recommendations). The approval of Recommendations by the Members of ITU-T is covered by the procedure laid down in WTSC
9、Resolution No. 1 (Helsinki, 1993). In addition, the World Telecommunication Standardization Conference (WTSC), which meets every four years, approves Recommendations submitted to it and establishes the study programme for the following period. In some areas of information technology which fall withi
10、n ITU-Ts purview, the necessary standards are prepared on a collaborative basis with IS0 and IEC. The text of ITU-T Recommendation X.634 was approved on 5th of October 1996. The identical text is also published as ISOAEC International Standard 14699. NOTE In this Recommendation, the expression “Admi
11、nistration” is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. O IT 1997 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 microf
12、ilm, without permission in writing from the ITU, except as noted in footnote 2) in Annex A. i ITU-T Rec. X.634 (1996 E) CONTENTS Scope Normative references . 2.1 Identical Recommendations I Intemational Standards 2.2 Paired Recommendations 1 International Standards equivalent in technical contents .
13、 Definitions Symbols and abbreviations . 4.1 Data units 4.2 TPDU types . 4.3 TPDU fields 4.4 Miscellaneous . Overview ofthe Transport Fast Byte Protocol . Service provided by the Transport Layer Functions of the Transport Layer 5.1 5.2 Service assumed from the Network 5.3 5.4 Modes of operation . 5.
14、5 Model of the Transport Layer . Transport Fast Byte Protocol specification 6.1 6.2 Connection establishment . 6.3 Connection refusal 6.4 Normal release 6.5 Error indication . 6.6 Abnormal release 6.7 Data transfer Transport Protocol Data Unit (TPDU) transfer . 6.8 Segmenting and reassembling . 6.9
15、Expedited data transfer . 6.10 Invalid TPDU FB-TPDU structure and encoding 7.2 Control part . 7.3 Data part Conformance 7.1 Header part Annex A . Protocol Implementation Conformance Statement (PICS) profoxma A.l General A.2 Identification . A.3 Indices used in this annex . A.4 Modes implemented AS I
16、nitiatorhesponder capability to establish connection . A.6 Supported functions A.7 Supported TPDUs . A.8 Supported FB-TPDU fields and parameters . A.9 Negotiation and selection A . 1 O Error handling . Annex B - Fallback procedures for systems implementing ITU-T Rec . X.224 I ISO/IEC 8073 in additio
17、n to the Transport Fast Byte Protocol B.l Scope . B.2 Fallback procedures 11 ITU-T Rec . X.634 (1996 E) Page 1 1 1 2 2 3 3 3 3 3 4 4 5 6 6 7 7 8 8 9 10 11 11 11 12 12 13 13 13 14 15 16 17 17 17 18 18 18 18 19 19 19 20 21 21 21 Summary The Transport Fast Byte Protocol eliminates the round trip delay
18、associated with the establishment and release of a transport connection, and requires very low PCI overhead. The Transport Fast Byte Protocol is intended for use in situations in which enhancements to the network QOS are not required, and efficiency of operation (e.g. reduction of round trip delays
19、on establishment and release) is of primary concern. Introduction This Recommendation I International Standard is one of a set of Recommendations I International Standards produced to facilitate the interconnection of information processing systems. This set of Recommendations I Intemational Standar
20、ds covers the services and protocols required to achieve such interconnection. The Transport Fast Byte Protocol Recommendation Intemational Standard is positioned with respect to other related Recommendations I International Standards by the layers defined in the Reference Model for Open Systems Int
21、erconnection (see ITU-T Rec. X.200 I ISOAEC 7498-1). It is most closely related to, and lies within the field of application of, the Transport Service definition (see ITU-T Rec. X.214 I ISO/IEC 8072). It also uses and makes reference to the Network Service defmition (see ITU-T Rec. X.213 I ISOAEC 83
22、48), whose provisions it assumes in order to accomplish Transport Fast Bytes aims. The interrelationship of these Recommendations I International Standards is illustrated in Figure Intro. 1. Transport Service definition I Reference to aims - - - - - I - Reference to assumptions - -, - Transport Fast
23、 Byte specification I v Network Service definition Figure Intro. 1 - Relationship between the Transport Fast Byte Protocol and adjacent services This Recommendation 1 International Standard specifies a common encoding and protocol procedures. It is intended that the Transport Fast Byte Protocol shou
24、ld be simple and cater for a specific range of Network Service qualities possible. The protocol is structured to give rise to two modes of operation which are designed to minimize possible incompatibilities and implementation costs. The modes are selectable with respect to the Transport and Network
25、services in providing the required Quality of Service for the interconnection of two session entities (one mode ignores network signalled errors, the other mode does not). This Recommendation I International Standard does not define mechanisms that can be used to optimize network tariffs or enhance
26、the quality of Network Service. . ITU-T Rec. X.634 (1996 E) 111 STD-ITU-T RECMN Xmb34-ENGL 177b W 4b259L Ob285qb O0 m The primary aim of this Recommendation I Intemational Standard is to provide a set of rules for communication expressed in terms of the procedures to be carried out by peer entities
27、at the time of communication. These rules for communication are intended to provide a sound basis for development in order to serve a variety of purposes: a) b) c) d) as a guide for implementors and designers; for use in the testing and procurement of equipment; as part of an agreement for the admit
28、tance of systems into the open systems environment; as a refinement of the understanding of OSI. As it is expected that the initial users of this Recommendation I International Standard will be designers and implementors of equipment, this Recommendation I Intemational Standard contains, in notes or
29、 in annexes, guidance on the implementation of the procedures defned herein. This Recommendation I International Standard contains a clause on conformance of equipment claiming to implement the procedures in this Recommendation I International Standard (see clause 8). To evaluate conformance of a pa
30、rticular implementation, it is necessary to have a statement of which capabilities and options have been implemented for a given OS1 protocol. Such a statement is called a Protocol Implementation Conformance Statement (PICS). A PICS proforma is provided in Annex A. Attention is drawn to the fact tha
31、t this Recommendation I International Standard does not contain any tests to demonstrate this conformance. It should be noted that it may not be possible with current technology to verify that an implementation will operate the protocol defned in this Recommendation I International Standard correctl
32、y under all circumstances. It is possible by means of testing to establish confidence that an implementation correctly operates the protocol in a representative sample of circumstances. It is, however, intended that this Recommendation I International Standard can be used in circumstances where two
33、implementations fail to communicate in order to determine whether one or both have failed to operate the protocol correctly. iv ITU-T Rec. X.634 (1996 E) STD-ITU-T RECflN X-bIi-ENGL L77b = 48b257L Ob28547 TL7 ISO/IEC 14699 : 1997 (E) INTERNATIONAL STANDARD ITU-T RECOMMENDATION INFORMATION TECHNOLOGY
34、 - OPEN SYSTEMS INTERCONNECTION - TRANSPORT FAST BYTE PROTOCOL 1 Scope This Recommendation I International Standard specifies: a) Two modes of procedures when operating over the connection oriented network service: 1) 2) for the connection oriented transfer of data and control information from one t
35、ransport entity to a peer transport entity. mode O: acts on network signalled errors; mode 4: ignores network signalled errors, b) c) The means of selecting the mode of procedures to be used by the transport entities. The structure and encoding of the TPDUs used for the transfer of data and control
36、information. The procedures are defined in terms of: a) b) c) the interactions between peer transport entities through the exchange of TPDUs; the interactions between a transport entity and the transport service user in the same system through the exchange of transport service primitives; the intera
37、ctions between a transport entity and the network service provider through the exchange of network service primitives. These procedures are applicable to instances of communication between systems which support the Transport Layer of the OS1 Reference Model and wish to interconnect in the open syste
38、ms environment using the Transport Fast Byte Protocol. This Recommendation I International Standard specifies, in clause 8, conformance requirements for systems implementing these procedures and provides the PICS proforma in compliance with the relevant requirements, and in accordance with the relev
39、ant guidance, given in ITU-T Rec. X.296 and ISO/IEC 9646-7. It does not contain tests which can be used to demonstrate this conformance. 2 Normative references The following Recommendations and International Standards contain provisions which, through reference in this text, constitute provisions of
40、 this Recommendation I Intemational Standard. At the time of publication, the editions indicated were valid. All Recommendations and Intemational Standards are subject to revision, and parties to agreements based on this Recommendation I International Standard are encouraged to investigate the possi
41、bility of applying the most recent edition of the Recommendations and International Standards listed below. Members of IEC and IS0 maintain registers of currently valid International Standards. The Telecommunication Standardization Bureau of the ITU maintains a list of currently valid IT-T Recommend
42、ations. 2.1 Identical Recommendations I International Standards - ITU-T Recommendation X.200 (1994) I ISOAEC 7498-1:1994, Information technology - Open Sstems Interconnection - Basic Reference Model: The Basic Model, IT-T Recommendation X.2 10 (1 993) I ISOAEC 1073 1 : 1994, Information technology -
43、 Open Systems Interconnection - Basic Reference Model: Conventions for the definition of OSI services. IT-T Recommendation X.213 (1995) I ISOAEC 8348:1996, Information technology - Open Sstems Interconnection - Network service definition. - - ITU-T Rec. X.634 (1996 E) 1 STD-ITU-T RECMN XOb3Li-ENGL L
44、77b M L1Ab259L Ob285LiB 953 ISOIEC 14699 : 1997 (E) - IT-T Recommendation X.214 (1995) I ISOAEC 8072:1996, Information technology - Open Systems Interconnection - Transport service definition. IT-T Recommendation X.224 (1995) 1 ISOAEC 8073:1997, Information technology - Open Systems Interconnection
45、- Protocol for providing the OSI connection-mode transport service. ITU-T Recommendation X.263 (1995) I ISOAEC TR 9577 .I, Infarmation technology - Protocol identifmxtion in the Network layer. - - 2.2 Paired Recommendations I International Standards equivalent in technical contents - ITU-T Recommend
46、ation X.290 (1999, OSI conformance testing methodology and pamework for protocol Recommendations for ITU-T applications - General Concepts. ISO/IEC 9646- 1 : 1994, Information technology - Open Systems Interconnection - Conformance testing methodology andfiamework - Part I: General concepts. ITU-T R
47、ecommendation X.296 (1995), OSI conformance testing methodology and pamework for protocol Recommendations for ITU-T applications - Implementation conformance statements. ISOIIEC 9646-7: 1995, Information technology - Open Systems Interconnection - Conformance testing methodology and pamework - Part
48、7: Implementation Conformance Statements. - 3 Definitions NOTE - The definitions contained in this clause make use of abbreviations defined in clause 4. This Recommendation I International Standard is based on the concepts developed in ITU-T Rec. X.200 I a) concatenation and separation; b) segmentin
49、g and reassembling; c) multiplexing and demultiplexing; d) splitting and recombining; e) flow control; f) nil selector value; g) connection-mode network service; h) connection-mode transport service. For the purposes of this Recommendation I Intemational Standard, the following definitions apply: equipment: Hardware or software or a combination of both; it need not be physically distinct within a local matter: A decision made by a system concerning its behaviour in the Transport Layer that is not subject initiator: A transport entity that acts on a T-CONNECT requ
