GB/T 16974-2009Information technology -- Data communications -- X.25 Packet Layer Protocol for Data Terminal Equipment (English PDF)

Foreword

This standard is equivalent to ISO/IEC 8208.:2000 "Information technology data communication data terminal equipment X. 25 cladding agreement "(English version).

This standard replaces GB/T 16974-1997 "Information technology data communication data terminal equipment X. 25 cladding agreement ".

This standard compared with GB/T 16974-1997, the main changes are as follows.

a) Increased the module extension number of the module 32768, which includes.

--- new module 32768 operation of the package format;

- When using modulo 32768 operation, a protocol identifier field is used;

--- a new super-extended packet sequence number facility;

--- modified non-standard default window size facilities;

--- modify the flow control parameters negotiation facility.

b) Expanded A bit = 1 (TOA/NPI addressing) Performance.

--- Added support for A bit = 1 addressing address type and numbering scheme;

--- Expanded use of A bit = 1 addressing in call setup and purge packets;

--- Added TOA/NPI address reservation facility;

--- Expanded performance in alternative addressing related facilities;

Added diagnostic code # 46.

c) Modifications associated with the online facility registration facility.

--- indicate X. 251996 version of the online registration facility was deleted;

--- Increased the ability of the online facility registration facility to modulate the non-standard default window size for modulo 32768 operations.

Appendix A and B of this standard are normative and Appendix C, Appendix D is an informative appendix.

This standard is proposed and centralized by the National Information Standardization Technical Committee.

The drafting unit of this standard. China Electronic Technology Standardization Institute.

1 Scope

This standard specifies that the data terminal equipment (DTE) operation is in accordance with ITU-TX. 25 of the cladding procedures, formats and facilities. include Virtual call and permanent virtual circuit two modes of operation.

The standard protocol can be used for open system interconnection (OSI) and non-OSI. When used in OSI context, package Layer protocol package in the OSI reference model of the network layer, that is, GB/T 9387.1-1998.

When accessed by means of a dedicated path or circuit switched connection to ITU-TX. 25 of the public or private packet switching network when this standard package the DTE operation on the cladding. This standard also includes two DTEs conforming to this standard, via dedicated paths, circuit switched connections, or local area networks (LAN) direct communication (without packet switching network intervention) necessary additional packet procedures.

This standard also includes the use of ITU-TX. 25 is connected to the packet-switched public data network and can also provide X for the DTE. 25 interface Use the network (see Appendix A).

In order to assess the consistency of a particular implementation, there is a need for those capabilities and options that are fulfilled. This statement is called "agreement to achieve one." (PICS), as defined in ISO/IEC 9646-7.:1997, is defined in ISO/IEC 9646-7.:1997.

Record B provides a PICS form.

The first edition of the corresponding international standard was based on 1984CCITTX. 25 of the Redbooks are based on the text, also included with the early 1980 CCITTX. 25 of the Yellow Book is compatible with the necessary terms. The second edition is based on 1988CCITTX. 25 of the Blue Book text is based, the third edition is based on X. 25 of the 1993 version is based on the four edition is X. 25 of the 1996 edition. Which includes the 1988, 1984 and 1980X. 25 version compatible with the necessary terms. Differences between the different versions of this standard are summarized in Appendix C.

It should be noted that when used in DTE, this standard is compatible with ITU-TX. 25 is not the same. This standard contains ITU-TX. 25 on the DTE specification. In addition, this standard also includes DTE to DTE to work between DTE and DTE Additional specification. This broader scope of application must be recognized in the application of this standard.

2 Normative reference documents

The terms of the following documents are hereby incorporated by reference into this standard. Whichever is the date of the reference file, which is followed by all (Excluding corrigenda) or revisions do not apply to this standard, however, encourage the parties to reach an agreement under this standard Whether you can use the latest version of these files. For undated references, the latest edition applies to this standard.