ISO IEC 8882-3 pdf download.Information technology – Telecommunications and information exchange between systems – X.25 DTE conformance testing
This part of ISOIIEC 8882 specifies a set of abstract tests for verifying that the implementation of X.25 protocols for use by Data Terminal Equipment (DTE), conforms to the requirements of International Standards that specify those protocols. Testing of a DCE is not subject of this test suite. Testing of a DTE in DCE mode is covered in test group 28 of this test suite a) specifies a PIXIT proforma; b) c) d) describes the relationship of the PICS to the test suite, describes the relationship of the PIXIT to the test suite, specifies a set of abstract tests using TTCN Graphical notation. This part of ISOIIEC 8882 defines the testing of a DTE operating at the packet layer designed to access a public or private packet-switched network conforming to CCIlT respectively ITU-T Recommendation X.25 (1980, 1 984, 1988, 1 993) or another DTE conforming to IS0 8208. The specification of test cases in executablelmachine processable TTCN is outside the scope of this part of ISOIIEC 8882.
2 Normative references
The following standards contain provisions 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 possibility 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 :I 994, Information technology – Open Systems Interconnection – Basic Reference Model: The Basic Model. (See also ITU-T Recornmendation X.200) ISOIIEC 7776:1995, 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 8208:1987, Information processing systems – Data communication – X.25 Packet Layer Protocol for Data Terminal Equipment. ISOIIEC 8208:1990, Information technology – Data communication – X.25 Packet Layer Protocol for Data Terminal Equipment. ISOIIEC 8208:1995, Information technology – Data communication – X.25 Packet Layer Protocol for Data Terminal Equipment. ISOIIEC 8824: 1990, Information technology – Open Systems Interconnection – Specification of Abstract Syntax Notation One (ASN. I}. ISOIIEC 8882-1 :1996, Information technology – Telecommunications and information exchange between systems – X.25 DTE conformance testing – Part 1: General principles. ISOIIEC 8886:1992, Information technology – Telecommunications and information exchange between systems – Data link service definition for Open Systems Interconnection. ISOIIEC 9646-1 :I 994, Information technology – Open Systems Interconnection – Conformance testing methodology and framework- fart 7: General concepts. (See also ITU-T Recommendation X.290)
6.2 Packet layer initialization
In accordance with IS0 8208 (1987, 1990, 1995) the DTE must transmit a Restart Request whenever link layer initialization has completed. However, DTEs developed in conformance with the 1980, 1984, 1988, and 1993 versions of Recommendation X.25 are not required to send a Restart Request at this time. To accommodate both DTE implementations, the Tester initiates the restart procedure upon completion of link layer initialization. The Tester will accept either a Restart Confirmation or a Restart Request as a valid response to its Restart Indication as shown below in example EG-001. Packet layer initialization always occurs once at the start of a test session. State initialization, on the other hand, is performed many times during a test session as part of each test case. Packet layer initialization will also occur as part of state initialization when the previously executed test case results in a Fail or Inconclusive verdict, or the previously executed test case is part of PLG 1, 2, 3, 26 or in test groups in which the Restart procedure is executed as part of state initialization (PLG 1 , 2. 3 and 26). The following are examples of initialization of IS0 8208 over IS0 7776 (LAPB). Any other examples of initialization sequences using other underlying protocols are not shown, but may be appropriate. For example, normal state initialization steps in state r l (PLG 1) are as shown in Table 2. For those DTEs which disconnect the link upon receipt of a Restart Indication (or transmittal of a Restart Request) the state initialization steps include link layer initialization as shown in Table 3.