BS ISO IEC 10030-1995 Information technology - Telecommunications and information exchange between systems - End System Routeing Information Exchange protocol for use in conjunctio.pdf

1、BRITISH STANDARD BS ISO/IEC 10030:1995 Implementation of ISO/IEC10030:1995 Information technology Telecommunications and information exchange between systems End System Routeing Information Exchange Protocol for use in conjunction with ISO/IEC8878 UDC 681.3:621.39BSISO/IEC10030:1995 This BritishStan

2、dard, having been prepared under the directionof the Information Systems Technology Assembly, was published under the authorityof the Standards Boardand comes into effect on 15September1995 BSI01-2000 First edition April1991 Second edition August1995 The following BSI references relate to the work o

3、n this standard: Committee reference IST/6 Draft for comment94/644337 DC ISBN 0 580 19624 0 Committees responsible for this BritishStandard The preparation of this BritishStandard was entrusted to Technical Committee IST/6, Data communications, upon which the following bodies were represented: Briti

4、sh Computer Society British Telecommunications plc CCTA (the Government Centre for Information Systems) Digital Equipment Co. Ltd. IBM United Kingdom Ltd. Institution of Electrical Engineers International Computers Limited Nine Tiles Computer Systems Ltd. Logica UK Ltd. Rank Xerox (UK) Ltd. Amendmen

5、ts issued since publication Amd. No. Date CommentsBSISO/IEC10030:1995 BSI 01-2000 i Contents Page Committees responsible Inside front cover National foreword ii Foreword iii Text of ISO/IEC10030 1BSISO/IEC10030:1995 ii BSI 01-2000 National foreword This BritishStandard reproduces verbatim ISO/IEC100

6、30:1995 and implements it as the UK national standard. It supersedes BS ISO/IEC10030:1991 which is withdrawn. This BritishStandard is published under the direction of the Information Systems Technology Assembly whose Technical Committee IST/6 has the responsibility to: aid enquirers to understand th

7、e text; present to the responsible international committee any enquiries on interpretation, or proposals for change, and keep UK interests informed; monitor related international and European developments and promulgate them in the UK. NOTEInternational and European Standards, as well as overseas st

8、andards, are available from Customer Services, BSI,389 Chiswick High Road, London W44AL. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of

9、 itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, theISO/IEC title page, pages ii to iv, pages1 to31 and a back cover. This standard has been updated (see copyright date) and may have had amendments incorpor

10、ated. This will be indicated in the amendment table on the inside front cover.ISO/IEC10030:1995(E) ii BSI 01-2000 Contents Page Foreword iii Introduction 1 1 Scope 1 2 Normative references 2 3 Definitions 3 4 Abbreviations 3 5 Overview of the Protocol 4 6 Conformance 5 7 SNARE Subnetwork Address 6 8

11、 Configuration Information Subset 6 9 System Redirection Information Subset 10 10 Address and SNPA Masks 12 11 SNARE Procedures 13 12 Structure and Encoding of PDUs 15 Annex A (normative) Obtaining SNARE SNPA Addresses using LLC Type1 Procedures 20 Annex B (normative) Protocol Implementation Conform

12、ance Statement Proforma 21 Annex C (informative) ES Procedures when SNARE NET repository is depleted 31 Figure 1 Network Address Parameter 15 Figure 2 SNPA Address Parameter 15 Figure 3 Encoding of QOS Parameters 16 Figure 4 ECQ PDU Structure 18 Figure 5 ENC PDU Structure 18 Figure 6 ESC PDU Structu

13、re 18 Figure 7 ESH PDU Structure 18 Figure 8 RD PDU Structure 18 Figure 9 SCC PDU Structure 18 Figure 10 SCR PDU Structure 19 Figure 11 SNC PDU Structure 19 Figure 12 SRN PDU Structure 19 Figure 13 ERA PDU Structure 19 Figure 14 SAA PDU Structure 19 Figure A.1 SHL PDU Structure 21 Figure A.2 SRH PDU

14、 Structure 21 Table 1 Valid PDU Types 15ISO/IEC10030:1995(E) BSI 01-2000 iii Foreword ISO (the International Organization for Standardization) and IEC (theInternational Electrotechnical Commission) form the specialized system for worldwide standardization. National bodies that are members of ISO or

15、IEC participate in the development of International Standards through technical committees established by the respective organization to deal with particular fields of technical activity. ISO and IEC technical committees collaborate in fields of mutual interest. Other international organizations, go

16、vernmental and non-governmental, in liaison with ISO and IEC, also take part in the work. In the field of information technology, ISO and IEC have established a joint technical committee, ISO/IEC JTC1. Draft International Standards adopted by the joint technical committee are circulated to national

17、bodies for voting. Publication as an International Standard requires approval by at least75% of the national bodies casting a vote. International Standard ISO/IEC10030 was prepared by Joint Technical Committee ISO/IEC JTC1, Information technology, Subcommittee SC6, Telecommunications and information

18、 exchange between systems. This second edition cancels and replaces the first edition (ISO10030:1990), which has been technically revised. It is a consolidation of Amendments2 and3 as well as Technical Corrigenda1 and2. Annex A and Annex B form an integral part of this International Standard. Annex

19、C is for information only.iv blankISO/IEC10030:1995(E) BSI 01-2000 1 Introduction This International Standard is one of a number of standards concerned with Network Layer Routeing Protocols. An overall framework for routeing is described in ISO/IEC TR9575. This International Standard specifically re

20、lates to that part of the framework which deals with Single Subnetwork Routeing. This International Standard is related to ISO/IEC8878 which specifies the use ofX.25 to provide the ISO connection-mode Network Service. This Protocol provides solutions for the following practical problems: a) How do E

21、nd Systems discover the reachability of Intermediate Systems that can route NPDUs to destinations on subnetworks other than the one(s) to which the End System is directly connected? b) How do End Systems discover the reachability of other End Systems on the same subnetwork (when direct examination o

22、f the destination NSAP address does not provide information about the destination subnetwork address)? c) How does a Subnetwork Address Resolution Entity discover the reachability of End Systems on the subnetwork to which it is directly connected? d) How does an end System, which has not been pre-co

23、nfigured with its own Network Address, request the temporary assignment of a Network Entity Title (NET) and thus, derive the necessary Network Address(es), from a SNARE located on a common subnetwork? e) How do Intermediate systems discover the reachability of End Systems on the same subnetwork (whe

24、n direct examination of the NSAP destination address does not provide information about the destination subnetwork address)? The Protocol assumes that: a) Routeing to a specified subnetwork point of attachment (SNPA) address on the same subnetwork is carried out satisfactorily by the subnetwork itse

25、lf. b) The subnetwork is not, however, capable of routeing on a global basis using the NSAP address alone to achieve communication with a requested destination. c) End Systems and Intermediate Systems using this protocol require to know at least one SNPA address that can be used to access a SNARE. T

26、he protocol is designed to: a) minimize the amount of a priori state information needed by End Systems before they can begin to communicate with other End Systems; b) minimize the amount of memory needed to store routeing information in End Systems; and c) minimize the computational complexity of En

27、d Systems routeing algorithms. This Protocol performs similar functions to the ones specified in ISO9542. However, the characteristics of environments operating ISO/IEC8208 (X.25/PLP) and the actual functionality of ISO/IEC8208(X.25/PLP) in itself invalidate the operation of ISO9542 as follows: a) I

28、n general non-broadcast environments, the Configuration subset of ISO9542 is inadequate. b) In broadcast environments operating ISO/IEC8208(X.25/PLP), the Redirection subset of ISO9542 is invalidated. Therefore, this Protocol is developed to perform all the aforementioned functions in harmony with t

29、he operation of ISO/IEC8208(X.25/PLP). 1 Scope This International Standard defines a protocol for the exchange of routeing information between an End System and a Subnetwork Address Resolution Entity, and between an Intermediate System and a Subnetwork Address Resolution Entity. This International S

30、tandard is applicable to: a) End Systems which operate according to the main body of ISO/IEC8878 to provide and support the OSI Connection-mode Network Service using ISO/IEC8208. b) Subnetwork Address Resolution Entities which operate ISO/IEC8208. NOTEThe Subnetwork Address Resolution Entity defined

31、 in this International Standard may be associated with relay functions as defined in ISO/IEC10028 and ISO/IEC10177. c) Intermediate systems which operate ISO/IEC8208. End Systems which provide and support the OSI CONS using the fast select1980 procedures or the alternative1980 procedures in AnnexA o

32、f ISO/IEC8878 are outside the scope of this International Standard. This International Standard does not specify any protocol elements nor algorithms for facilitating routeing and relaying among SNAREs. Such functions are intentionally outside the scope of this International Standard.ISO/IEC10030:19

33、95(E) 2 BSI 01-2000 To evaluate conformance of a particular implementation, it is necessary to have a statement of which capabilities and options have been implemented. Such a statement is called Protocol Implementation Conformance Statement (PICS), as defined in ISO/IEC9646-1. This International St

34、andard provides the PICS proforma in compliance with the relevant requirements, and in accordance with the relevant guidance, given in ISO9646-7. 2 Normative references The following standards contain provisions which, through reference in the text, constitute provisions of this International Standa

35、rd. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. Members of IEC

36、 and ISO maintain registers of currently valid International Standards. ISO/IEC7498-1:1994, Information technology Open Systems Interconnection Basic Reference Model Part1: The Basic Model. ISO/IEC8208:1990, Information technology Data communications X.25 Packet Layer Protocol for Data Terminal Equi

37、pment. ISO/IEC8208:1990/Amd.3:1991, Information technology Data communications X.25 Packet Layer Protocol for Data Terminal Equipment Amendment3: Conformance requirements. ISO/IEC8348:1993, Information technology Open Systems Interconnection Network Service Definition. ISO8648:1988, Information proc

38、essing systems Open Systems Interconnection Internal organization of the Network Layer. ISO8802-2:1989, Information processing systems Local area networks Part2: Logical link control. ISO/IEC8878:1992, Information technology Telecommunications and information exchange between systems Use of X.25 to

39、provide the OSI Connection-mode Network Service. ISO/IEC8880-1:1990, Information technology Telecommunications and information exchange between systems Protocol combinations to provide and support the OSI Network Service Part1:General principles. ISO/IEC8880-2:1992, Information technology Telecommun

40、ications and information exchange between systems Protocol combinations to provide and support the OSI Network Service Part2:Provision and support of the connection-mode Network Service. ISO/IEC8881:1989, Information processing systems Data communications Use of the X.25 packet level protocol in loc

41、al area networks. ISO/IEC8886:1992, Information technology Telecommunications and information exchange between systems Data link service definition for Open Systems Interconnection. ISO9542:1988, Information processing systems Telecommunications and information exchange between systems End system to

42、 Intermediate system routeing exchange protocol for use in conjunction with the Protocol for providing the connectionless-mode network service (ISO8473). ISO/IEC TR9575:1990, Information technology Telecommunications and information exchange between systems OSI Routeing Framework. ISO/IEC TR9577:199

43、3, Information technology Telecommunications and information exchange between systems Protocol identification in the network layer. ISO/IEC9646-1:1994, Information technology Open Systems Interconnection Conformance testing methodology and framework Part1:General concepts. ISO/IEC9646-7:, Informatio

44、n technology Open Systems Interconnection Conformance testing methodology and framework Part7:Implementation conformance statements 1) . ISO/IEC10028:1993, Information technology Telecommunications and information exchange between systems Definition of the relaying functions of a Network layer inter

45、mediate system. ISO/IEC10039:1991, Information technology Open Systems Interconnection Local area networks Medium Access Control (MAC) service definition. ISO/IEC10177:1993, Information technology Telecommunications and information exchange between systems Provision of the connection-mode Network in

46、ternal layer service by intermediate systems using ISO/IEC8208, theX.25 Packet Layer Protocol. ISO/IEC TR10178:1992, Information technology Telecommunications and information exchange between systems The structure and coding of Logical Link Control addresses in Local Area Networks. 1) To be publishe

47、d.ISO/IEC10030:1995(E) BSI 01-2000 3 3 Definitions 3.1 Reference Model Definitions This International Standard makes use of the following terms defined in ISO/IEC7498-1: a) Network Layer b) Network Service Access Point c) Network Service Access Point address d) Network Entity e) Routeing f) Network

48、Protocol g) Network Relay h) Network Protocol Data Unit 3.2 Network Layer Architecture Definitions This International Standard makes use of the following terms defined in ISO8648: a) Subnetwork b) End System c) Intermediate System d) Subnetwork Service e) Subnetwork Access Protocol 3.3 Network Layer

49、 Addressing Definitions This International Standard makes use of the following terms defined in ISO/IEC8348: a) Network Entity Titles b) Subnetwork address c) Subnetwork Point of Attachment 3.4 Local Area Network Definitions This International Standard makes use of the following terms defined in ISO8802-2: a) Multicast address b) Broadcast address 3.5 Additional Definitions For the purposes of the International Standard, the following definitions apply: 3.5.1 configuration information info