1、- STD-ITU-T RECMN Xmb33-ENGL L91b LiBb2591, 0628509 LO3 IOI INTERNATIONAL TELECOMMUNICATION UNION ITU=T TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU X.633 (1 0196) SERIES X: DATA NETWORKS AND OPEN SYSTEM COM M U N I CATI ON OS1 networking and system aspects - Efficiency Information technology - O
2、pen systems interconnection - Network Fast Byte Protocol ITU-T Recommendation X.633 (Previously “CCITT Recommendation“) STD.ITU-T RECMN Xmb33-ENGL L79b m 48b2591 Ob285LO 925 M ITU-T X-SERIES RECOMMENDATIONS DATA NETWORKS AND OPEN SYSTEM COMMUNICATION PUBLIC DATA NETWORKS X. I-X. 199 X.1-X.19 Service
3、s and facilities Interfaces X.20-X.49 Transmission, signalling and switching X.50-X.89 Network aspects X.90-X. 149 X. 150-X. 179 Maintenance X. 180-X. 199 Administrative arrangements OPEN SYSTEM INTERCONNECTION X.200-X.299 Model and notation X.200-X.209 Service definitions X.210-X.219 Connection-mod
4、e protocol specifications X.220-X.229 Connectionless-mode protocol specifications X.230-X.239 PICS proformas X.240-X.259 Protocol Identification X.260-X.269 Security Protocols X.270-X.279 Layer Managed Objects X.280-X.289 Conformance testing X.290-X.299 General X.300-X.349 INTERWORKING BETWEEN NETWO
5、RKS x.300-x.399 Satellite data transmission systems x.350-x.399 MESSAGE HANDLING SYSTEMS X.400-X.499 DIRECTORY X.500-X.599 OS1 NETWORKING AND SYSTEM ASPECTS X.600-X.699 Naming, Addressing and Registration X.650-X.679 X.680-X.699 Abstract Syntax Notation One (ASN. 1) OS1 MANAGEMENT X.700-X.799 System
6、s Management framework and architecture X.700-X.709 Management Communication Service and Protocol X.710-X.719 Structure of Management Information X.720-X.729 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 OPEN
7、DISTRIBUTED PROCESSING X.900-X.999 Management functions x.730-x.799 Remote operations X.880-X.899 For frther details, please refer to ITU-T List of Recommendations. STD-ITU-T RECMN X=b33-ENGL 177b lBb2571 Ob28511 Bbl M FOREWORD IT (International Telecommunication Union) is the United Nations Special
8、ized Agency in the field of telecommunications. The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of the ITU. Some 179 member countries, 84 telecom operating entities, 145 scientific and industrial organizations and 38 international organizations participate in IT-T which
9、 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 Resolution No. 1 (Helsinki, 1993). In addition, the World Telecommunication Standardization Conference (WTSC), which mee
10、ts 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 within IT-Ts purview, the necessary standards are prepared on a collaborative basis with IS0 and IEC. The text of IT-T Recomm
11、endation X.633 was approved on 5th of October 1996. The identical text is also published as ISOIEC International Standard 14700. NOTE In this Recommendation, the expression “Administration” is used for conciseness to indicate both a telecommunication administration and a recognized operating agency.
12、 O ITU 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 microfilm, without permission in writing from the IT, except as noted in footnote 2) in Annex A. ITU-T Rec. X.633 (1996 E) 1 CO
13、NTENTS Scope Normative references . 2.1 Identical Recommendations I Intemational Standards 2.2 Paired Recommendations I International Standards equivalent in technical contents . Definitions 3.1 This Recommendation I Intemational Standard is based on the concepts developed in ITU-T Rec . X.200 I ISO
14、AEC 7498-1 and makes use of the following terms defined in it: . 3.2 For the purposes of this Recommendation 1 Intemational Standard, the following definitions apply: 3.3 This Recommendation I International Standard uses the following terms defined in IT-T Rec . X.290 and ISOAEC 9646-1: . 3.4 This R
15、ecommendation I International Standard uses the following terms defined in ITU-T Rec . X.210 I ISOAEC 10731: Symbols and abbreviations . 4.1 Data units 4.2 NPDU types 4.3 NPDU fields 4.4 Miscellaneous . Overview ofthe Network Fast Byte Protocol 5.1 Service provided by the Network Layer . 5.2 Service
16、 assumed fiom the Data Link Layer 5.3 Functions of the Network Layer . 5.4 Operation over CODLS 5.5 Model of the Network Layer . Network Fast Byte Protocol specification 6.1 Network Protocol Data Unit (“DU) transfer 6.2 Connection establishment . 6.3 Connection refusal 6.4 Normal release 6.5 Error I
17、ndication . 6.6 Abnormal release 6.7 Data transfer 6.8 Segmenting and reassembling . 6.9 Qualifier-bit . 6.1 O Invalid NPDU . 6.1 1 NS-user initiated reset . FB-NPDU Structure and encoding . 7.1 Header part 7.2 Control part . 7.3 Data part Conformance Annex A . Protocol Implementation Conformance St
18、atement (PICS) proforma . A.l General A.2 Identification . A.3 Indices used in this annex . A.4 Initiatorhesponder capability to establish connection . A.5 Supported functions 11 ITU-T Rec . X.633 (1 996 E) Page 1 1 1 2 2 2 2 3 3 3 3 3 3 3 4 4 4 4 6 6 6 7 8 9 10 10 10 11 11 12 12 12 13 13 14 15 16 1
19、6 17 17 18 18 18 - STD-ITU-T RECMN Xmb33-ENGL L71L W 4b2571 Ob28513 b3Y m Page A.6 Supported NPDUs . 19 A.7 Supported FB NPDU fields and parameters 19 A.8 Negotiation and selection 19 A.9 Error handling . 20 16 B.l Applicable subnetworks 21 B.2 Fast Byte Protocol specification . 21 Annex B - Subnetw
20、ork Dependent Convergence Function for subnetworks employing out-of-band signalling . . ITU-T Rec. X.633 (1996 E) 111 - STD-ITU-T RECMN XOb33-ENGL 197b qBb2591 Ob2851q 570 M Network Fast Byte Specification Summary Network Service definition Reference to aims - - - - - - Reference to assumptions - -I
21、 I I -_ 7 Data Link Service definition The Network Fast Byte Protocol applies to the provision of the OS1 Connection-mode Network Service in end systems, and eliminates the round trip delay associated with the establishment and release of a network connection, and requires very low PCI overhead. The
22、 Network Fast Byte Protocol is intended for use in situations in which enhancements to the data link QOS are not required, and efficiency of operation (e.g. reduction of round trip delays on establishment and release) is of primary concern. Introduction This Recommendation I International Standard i
23、s one of a set of Recommendations I International Standards produced to facilitate the interconnection of information processing systems. This set of Recommendations I International Standards covers the services and protocols required to achieve such interconnection. The Network Fast Byte Protocol R
24、ecommendation I International Standard is positioned with respect to other related Recommendations I International Standards by the layers defined in the Reference Model for Open Systems Inter- connection (see ITU-T Rec. X.200 I ISODEC 7498-1). It is most closely related to, and lies within the fiel
25、d of application of the Network Service definition (ITU-T Rec. X.2 13 1 ISOIEC 8348). It also uses and makes reference to the Data Link Service definition (see ITU-T Rec. X212 I ISOAEC 8886), whose provisions it assumes in order to accomplish Network Fast Bytes aims. The interrelationship of these R
26、ecommendations 1 International Standards is illustrated in Figure Intro. 1. Figure Intro. 1 - Relationship between the Network Fast Byte Protocol and adjacent services This Recommendation I International Standard specifies a common encoding and protocol procedures. It is intended that the Network Fa
27、st Byte should be simple and cater for a specific range of Data Link Service qualities possible. This Recommendation I International Standard does not define mechanisms that can be used to optimize or enhance the quality of the Data Link Service. The primary aim of this Recommendation I Internationa
28、l Standard is to provide a set of rules for communication expressed in terms of the procedures to be camed out by peer entities 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
29、guide for implementors and designers; for use in the testing and procurement of equipment; as part of an agreement for the admittance of systems into the open systems environment; as a refinement of the understanding of OSI. iv ITU-T Rec. X.633 (1996 E) - - - STD-ITU-T RECMFJ Xmb33-ENGL 1i97b RI 4Bb
30、259l.1 Ob28525 407 As it is expected that the initial users of this Recommendation I International Standard will be designers and implementors of equipment, this contains, in notes or in annexes, guidance on the implementation of the procedures defined herein. This Recommendation I International Sta
31、ndard contains a clause on conformance of equipment claiming to implement the procedures in this Recommendation 1 International Standard (see clause 8). To evaluate conformance of a particular implementation, it is necessary to have a statement of which capabilities and options have been implemented
32、 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 that this Recommendation I International Standard does not contain any tests to demonstrate this conformance. It should
33、 be noted that it may not be possible with current technology to veri6 that an implementation will operate the protocol defined in this Recommendation I International Standard correctly under ali circumstances. It is possible by means of testing to establish confidence that an implementation correct
34、ly 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 implementations fail to communicate in order to determine whether one or both have failed to operate the protocol co
35、rrectly. ITU-T Rec. X.633 (1996 E) V ISO/iEC 14700 : 1997 (E) INTERNATIONAL STANDARD ITU-T RECOMMENDATION INFORMATION TECHNOLOGY NETWORK FAST BYTE PROTOCOL OPEN SYSTEMS INTERCONNECTION - 1 Scope This Recommendation I International Standard specifies: a) procedures when operating over the connection-
36、mode data link service for the connection-mode transfer of data and control information from one network entity to a peer network entity; the structure and encoding of the NPDUs used for the transfer of data and control information. b) The procedures are defined in terms of: a) b) the interactions b
37、etween peer network entities through the exchange of NPDUs; the interactions between a network entity and the network service user in the same system through the exchange of network service primitives; the interactions between a network entity and the data link service provider through the exchange
38、of data link service primitives. c) These procedures are applicable to instances of communication between systems which support the Network Layer of the OS1 Reference Model and wish to interconnect in the open systems environment using the Network Fast Byte Protocol. This Recommendation I Internatio
39、nal 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 relevant guidance, given in ITU-T Rec. X.296 and ISOLEC 9646-7. It does not contain tests wh
40、ich 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 this Recommendation I International Standard. At the time of publication, the editions
41、indicated were valid. All Recommendations and Intemational Standards are subject to revision and parties to agreements based on this Recommendation 1 Intemational Standard are encouraged to investigate the possibility of applying the most recent edition of the Recommendations and International Stand
42、ards 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 ITU-T Recommendations. 2.1 Identical Recommendations I International Standards - ITU-T Recommendation X
43、.200 (1994) I ISO/IEC 7498-1:1994, Information technology - Open Systems Interconnection - Basic Reference Model: fie Basic Model. ITU-T Recommendation X.2 1 O (1993) I ISOLEC 1073 1 : 1994, Information technology - Open Systems Interconnection - Basic Reference Model: Conventions for the de3nition
44、of OSI services. ITU-T Recommendation X.212 (1995) I ISOLEC 8886:1996, Information technology - Open Systems Interconnection - Data link service defmition. - - ITU-T Rec. X.633 (1996 E) 1 STD=ITU-T RECMN Xmb33-ENGL 199b W 48b2571 Ub28518 LLb ISO/IEC 14700 : 1997 (E) - ITU-T Recommendation X.213 (199
45、5) I ISOiEC 8348:1996, Information technology - Open Systems Interconnection - Network Service Definition. ITU-T Recommendation X.233 (1993) I ISOAEC 8473-1:1994, Information technology - Protocol for providing the connectionless-mode network service: Protocol specijkation. IT-T Recommendation X.263
46、 (1995) I ISOiEC TR 9577 .I), Information technology - Protocol identification in the Network layer. - - 2.2 Paired Recommendations I International Standards equivalent in technical contents - IT-T Recommendation X.223 (1993), Use of X25 to provide the OSI connection-mode network service for ITU-T a
47、pplications. ISOAEC 8878: 1992, Information technology - Telecommunications and information exchange between systems - Use of X 25 to provide the OSI Connection-mode Network Service. ITU-T Recommendation X.290 (1995), OSI conformance testing methodology and jkamework jr protocol Recommendations for
48、ITU-T applications - General concepts. ISOAEC 9646- 1 : 1994, Information technology - Open Systems Interconnection - Conformance testing methodology andpamework - Part I: General concepts. ITU-T Recommendation X.296 (1995), OSI conformance testing methodology and fi-amework for protocol Recommendat
49、ions for ITU-T applications - Implementation conformance statements. ISOAEC 9646-7:1995, Information technology - Open Systems Interconnection - Conformance :es fing methodology andpamework - Part 7: Implementation Conformance Statements. - - 3 Definitions NOTE - The definitions contained in this clause make use of abbreviations defined in clause 4. 3.1 ISOAEC 7498-1 and makes use of the following terms defined in it: This Recommendation I International Standard is based on the concepts developed in ITU-T Rec. X.200 I a) concaten
