ISO IEC 8882-2-2000 Information technology - Telecommunications and information exchange between systems - X 25 DTE conformance testing - Part 2 Data link layer.pdf

1、 STD-ISO 8882-2-ENGL 2000 4853903 083239b 74b m INTERNATIONAL ISOIIEC STANDARD 888212 Third edition 2000-04-1 5 Information technology - Telecom m u n i ca t i o ns and i n format i o n exchange between systems - X.25 DTE conformance testing - Part 2: Data link layer conformance test suite Technolog

2、ies de /information - Tlcommunications et change dinformation entre systmes - Test de conformit X.25 DTE - Parfie 2: Suite dessais de conformit pour la couche liaison de donnes Reference number ISO/I EC 8882-2:2000( E) Q ISOIIEC 2000 INTERNATIONAL STANDARD ISOIIEC 888213 Third edition 2000-04-1 5 In

3、formation technology - Telecommunications and information exchange between systems - X.25 DTE conformance testing - Part 3: Packet layer conformance test suite Technologies de linformation - Tlcommunications et change dinformation entre systmes - Test de conformit X.25 DTE - Partie 3: Suite dessais

4、de conformit pour la couche paquet Reference number ISOA EC 8882-3:2000( E) 0 ISOIIEC 2000 STD-IS0 BBBZ-Z-ENGL 2000 4853903 0832398 519 INTERNATIONAL STANDARD ISO/IEC 888212 Third edition 2000-04-1 5 Information technology - Telecommunications and information exchange between systems - X.25 DTE conf

5、ormance testing - Part 2: Data link layer conformance test suite Technologies de linformation - Tlcommunications et change dinformation entre systmes - Test de conformit X.25 DTE - Partie 2: Suite dessais de conformit pour la couche liaison de donnes Reference number I SOIIEC 8882-2:2000( E) Q ISOII

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10、sion in writing from either IS0 at the address below or ISOs member body in the country of the requester. IS0 copyright office Case postale 56 CH-I21 1 Geneva 20 Tel. + 41 22 749 O1 11 Fax + 41 22 734 10 79 E-mail copynghtiso.ch Web www.iso.ch Printed in Switzerland O ISOAEC 2000 -All rights resewed

11、 STD-IS0 8882-2-ENGL 2000 4851903 0832200 TT m ISOIIEC 8882-2:2000() Contents Page 1 . SCOPE i 2 . NORMATIVE REFERENCES 2 3 . DEFINITIONS AND ABBREVIATIONS 2 3.1 REFERENCE MODEL DEFINITIONS 3 3.2 CONFORMANCE TESTING TERMS . 3 3.3 X.25-DTE CONFORMANCE TESTING TERMS 4 3.4 ADDITIONAL DEFINITIONS 4 3.5

12、ABBREVIATIONS . 4 4 . TEST SUITE INFORMATION 4 4.1 TEST SUITE STRUCTURE 4 4.2 DATA LINK LAYER TEST GROUPS AND SUBGROUPS . 5 4.3. METHOD FOR CONFORMANCE TESTING 5 4.4 TEST CASE NOTATION 5 4.5 PREAMBLE 6 4.6 VERIFICATION SEQUENCE . 6 4.7 IUT INITIATED ACTIONS 7 4.8 ACCEPTABLE UNEXPECTED IUT FRAMES . 7

13、 4.9 TRANSIENT STATES 7 4.10 UNREACHABLE STATES 7 4.1 1 DECLARATIONS 7 4.12 ENCODING AND ORDER OF BIT TRANSMISSION 7 4.13 PIXIT PROFORMA . 8 4.14 CLASSIFICATION OF IUT . 9 ANNEX A ABSTRACT TEST SUITE (ATS) . 10 A.l THE TTCN GRAPHICAL FORM (TTCN.GR) 1 0 A.2 THE TTCN MACHINE PROCESSABLE FORM (TTCN.MP)

14、 . 10 O ISO/IEC 2000 -All rights reserved iii STD.IS0 8882-2-ENGL 2000 H 4853903 0832201 933 ISOIIEC 8882-2:2000(E) Foreword IS0 (the International Organization for Standardization) and IEC (the International Electrotechnical Commission) form the specialized system for worldwide standardization. Nat

15、ional bodies that are members of IS0 or IEC participate in the development of International Standards through technical committees established by the respective organization to deal with particular fields of technical activity. IS0 and IEC technical committees collaborate in fields of mutual interes

16、t. Other international organizations, governmental and non-governmental, in liaison with IS0 and IEC, also take part in the work. International Standards are drafted in accordance with the rules given in the ISOIIEC Directives, Part 3. In the field of information technology, IS0 and IEC have establi

17、shed a joint technical committee, ISOIIEC JTC 1. Draft International Standards adopted by the joint technical committee are circulated to national bodies for voting. Publication as an International Standard requires approval by at least 75 % of the national bodies casting a vote. Attention is drawn

18、to the possibility that some of the elements of this part of ISO/IEC 8882-2 may be the subject of patent rights. IS0 and IEC shall not be held responsible for identifying any or all such patent rights. International Standard ISOIIEC 8882-2 was prepared by Joint Technical Committee ISOIIEC JTC 1, Inf

19、ormation technology, Subcommittee SC 6, Telecommunications and information exchange between systems. This third edition cancels and replaces the second edition (ISOllEC 8882-2:1995), which has been technically revised. ISOIIEC 8882 consists of the following parts, under the general title Information

20、 technology - Telecommunications and information exchange between systems - X.25 DTE conformance testing: - Part I: General principles - Pari 2: Data iink layer conformance test suite - Part 3: Packet layer conformance test suite Annex A forms a normative part of this part of ISO/IEC 8882. iv O ISO/

21、IEC 2000 -All rights reserved ISOIIEC 8882-2:2000(E) Introduction This part of ISOIIEC 8882 presents the X.25-DTE Conformance Test Suite for Data Link Layer, described in Tree and Tabular Combined Notation (TTCN). ISOiiEC 8882-1 explains the objectives and usage of this part of ISOiIEC 8882. Clause

22、1 of this part of ISOIIEC 8882-2 is the scope which provides an objective basis for the applicability of the tests within this part of ISO/IEC 8882. Clauses 2 and 3 give the references, definitions and abbreviations used in this part of ISOilEC 8882. Clause 4 contains information relating to procedu

23、res performed in conformance testing. The test suite structure is defined in terms of test groups and subgroups in Table 1. This clause also gives an overview of the test suite. Annex A provides information on the Abstract Test Suite for the X.25-DTE LAPB Data Link Layer protocol both in TTCN GR and

24、 TTCN MP format. O ISOIIEC 2000 -All rights reserved V STD.ISO 8882-2-ENGL 2000 4851903 0832203 0b INTERNATIONAL STANDARD ISOllEC 8882-2:2000(E) Information technology - Telecommunications and information exchange between systems - X.25 DTE conformance testing - Part 2: Data link layer conformance t

25、est suite 1 Scope This part of ISOIIEC 8882 defines an abstract test suite for testing the conformance of the Data Link Layer of an IUT with respect to ISOllEC 7776 (1986,1995) or the ITU-T Recommendation X.25 (1980,1984,1988,1993). Conformance of a Data Terminal Equipment (DTE) to the above IS0 Int

26、ernational Standard or ITU-T Recommendations is tested using a dedicated circuit between the tester and the DTE. It is noted that ITU-T Recommendations X.25 (1980), X.25 (1984), X.25 (1988) and X.25 (1993) are written from the perspective of a DCE and therefore do not ahvays explicitly specify the D

27、TEs operation. In such cases it is assumed that recommended operation of a DTE is included by implication because of the need to communicate with X.25 DCEs. This part of ISOIIEC 8882 excludes the testing of the LAP procedures given in the ITU-T Recommendations. NOTE Test cases for extended mode oper

28、ation (Modulo 128), rnultilink procedure and DTE-DTE operation as per ISOIIEC 7776 are for further study. The tests in this part of ISO/IEC 8882 are designed for six possible interworking situations, shown in Figure 1. This part specifies tests for all six cases shown in Figure 1, but recognizes tha

29、t not every test may apply to a particular DTE. A test selection procedure has to be performed to determine the applicability of a test to a particular DTE. Such selection will be based on the PICS and the PIXIT. Local Station Remote Station DCE (X.25 LAPB 84) DTE (ISOIIEC 7776:1995) (based on ISOII

30、EC 7776:1995) DCE (X.25 LAPB 84) DTE (ISO/IEC 7776:1986) (based on ISOIIEC 7776:1986) (X.25 LAPB 93) (X.25 LAPB 80) Figure I - Testlng X.25-DTEIDCE and X.25-DTEIDTE Interworking Q ISOIIEC 2000 -All rights reserved 1 STD.ISO 8882-2-ENGL 2000 4851903 0832204 b42 ISOIIEC 8882-2:2000(E) In the rest of t

31、his part of ISOIIEC 8882, the term “X.25 standards“ means all four of ITU-T Recommendations X.25 (1980), X.25 (1984), X.25 (1988), X.25 (1993), and International Standards ISOIIEC 7776 (1995) and ISOIIEC 7776 (1986), unless stated otherwise. 2 Normative references The following standards contain pro

32、visions which, through reference in this text, constitute provisions of this part of ISOIIEC 8882. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this part of ISOIIEC 8882 are encouraged to investigate the poss

33、ibility of applying the most recent editions of the standards indicated below. Members of IEC and IS0 maintain registers of currently valid International Standards. ISOIIEC 7498-1:1994, Information technology - Open Systems Interconnection - Basic Reference Model: The Basic Model. (See also ITU-T Re

34、commendation X.200) ISOIl EC 7776: 1 995, Information technology - Telecommunications and information exchange between systems - High-level data link control procedures - Description of the X.25 LAPB-compatible DTE data link procedures. ISOIIEC 8824:1990, Information technology - Open Systems Interc

35、onnection - Specification of Abstract Syntax Notation One (ASN. I). ISOIIEC 8882-1 :1996, Information technology - Telecommunications and infomation exchange between systems - X.25-DTE conformance testing - Part 1: General principles. ISOIl EC 9646-1 :I 994, Information technology - Open Systems Int

36、erconnection - Conformance testing methodology and framework - Part I: General concepts. (See also ITU-T Recommendation X.290) ISOIIEC 9646-2:1994, Information technology - Open Systems Interconnection - Conformance testing methodology and framework - Part 2: Abstract Test Suite specification. (See

37、also ITU-T Recommendation X.291) ISOIIEC 9646-3: 1998, Information technology - Open Systems Interconnection - Conformance testing methodology and framework - Part 3: The Tree and Tabular Combined Notation (TTCN). ISOIIEC 9646-4: 1994, Information technology - Open Systems Interconnection - Conforma

38、nce testing methodology and framework - Part 4: Test realization. (See also TU-T Recommendation X.293) ISOIl EC 9646-51 994, Information technology - Open Systems Interconnection - Conformance testing methodology and framework - Part 5: Requirements on test laboratories and clients for the conforman

39、ce assessment process. (See also ITU-T Recommendation X.294) ITU-T Recommendations X.25 (1980), X.25 (1984). X.25 (1988), X.25 (1993), Interface between Data Terminating Equipment (DTE) and Data Circuit-terminating Equipment (OC) for terminals operating in the packet mode and connected to the public

40、 data networks by dedicated circuit. 3 Terms, definitions and abbreviations For the purposes of this part of ISOIIEC 8882, the terms and definitions given in 3.4 and in the following International Standards apply: a) ISO/IEC 7498-1; b) ISOIIEC 9646; C) ISOIIEC 8882-1. 2 O ISO/IEC 2000 -All rights re

41、served STD-IS0 8882-2-ENGL 2000 4853903 0832205 589 ISOIIEC 8882-2:2000(E) 3.1 Reference model terms The following terms defined in ISOllEC 7498-1 are used: a) b) Data Link Layer (N)-protocol data unit (N-PDU). In the context of this part of ISOllEC 8882-2. (N) is layer 2 and so N-PDU is abbreviated

42、 to PDU. A POU in the Daia Link Layer is also referred to as a “frame“. 3.2 Conformance testing terms The following terms are used from the Conformance Testing Methodology and Framework, International Standard ISOlIEC 9646: Conformance Testing Conformance Test Suite Implementation Under Test (IUT) P

43、rotocol Implementation Conformance Statement (PICS) Protocol Implementation Extra Information for Testing (PIXIT) Static Conformance Requirements (SCR) Behavior Testing Test Purpose Tree and Tabular Combined Notation (TTCN) Preamble Test Body Test Step Test Event Abstract Service Primitive (ASP) Tes

44、t Group Abstract Test Suite (ATS) Executable Test Suite (ETS) Test Verdicts Lower Tester Upper Tester Test Methods Remote Single (layer) Test Method (RS method) Valid Test Event Invalid Test Event Inopportune Test Event Point of Control and Observation (PCO) O ISOAEC 2000 -All rights reserved 3 STD.

45、IS0 82-2-ENGL 2000 48511903 083220b 4115 - ISOIIEC 8882-2:2000(E) 3.3 X.25-DTE conformance testing terms This pari of ISOIIEC 8882-2 makes use of the following terms defined in ISOAEC 8882-1 : a) Improper PDU b) Proper PDU c) TestCase d) Test Subgroup e) Tester 3.4 Additional terms and definitions T

46、his test suite uses test subgroups for proper, improper and inopportune frames to test the IUT behavior. These terms are defined below. 3.4.1 improper frame frame that satisfies one or more of the following conditions: a) b) c) d) e) it is not properly bounded by two flags; it contains fewer than 32

47、 bits between flags; it contains a Frame Check Sequence (FCS) error: it contains an invalid address field encoding; it contains a command or response control field encoding that is undefined or not implemented in X.25-DTE LAPB Data Link Layer protocol as specified in ISO/IEC 7776; it is an I frame e

48、xceeding the maximum established frame length; it is an unnumbered or supervisory frame with an information field which is not permitted; it is a frame with an invalid N(R) f) g) h) 3.4.2 inopportune frame syntactically valid frame arriving at a time (DTEs state) when it should be considered irrelev

49、ant by the DTE. Syntactically valid frames are those that are allowed by the X.25 standards for a DTE using the LAPB procedure and are not covered by 3.4.1 3.4.3 proper frame valid frame arriving at the correct DTEs state or phase and not covered by 3.4.1 or 3.4.2 3.5 Abbreviations The abbreviation IUT is used in this part of ISOllEC 8882-2 to refer to an X.25-DTE under test. 4 Test suite information 4.1 Test suite structure The X.25-DTE Data Link Layer Conformance Test Suite structure is outlined in Table I. 4 O ISO