1

Scope

This part of ISO/IEC 10021 defines the abstract-service provided by the MTS (the MTS Abstract Service), and specifies the procedures to be performed by MTAs to ensure the correct distributed operation of the MTS.

ISO/IEC 10021-2 identifies the other International Standards which define other aspects of Message Handling Systems.

Access to the MTS Abstract Service defined in this part of ISO/IEC 10021 may be provided by the MTS Access Protocol (P3) defined in ISO/IEC 10021-6. The distributed operation of the MTS defined in this part of ISO/IEC 10021 may be provided by the use of the MTS Transfer Protocol (P1) also defined in ISO/IEC 10021-6.

Section two of this part of ISO/IEC 10021 defines the MTS Abstract Service. Clause 6 describes the Message Transfer System Model. Clause 7 provides an overview of the MTS Abstract Service. Clause 8 defines the semantics of the parameters of the MTS Abstract Service. Clause 9 defines the abstract-syntax of t he MTS Abstract Service.

Section three of this part of ISO/IEC 10021 defines the MTA Abstract Service. Clause 10 refines the model of the MTS, first p resented in clause 6, to show that the MTS comprises a number of MTAs that interwork with one another to provide the MTS Abstract Service. Clause 11 provides an overview of the MTA Abstract Service. Clause 12 defines the semantics of the parameters of the MTA Abstract Service. Clause 13 defines the abstract-syntax of the MTA Abstract Service.

Section four of this part of ISO/IEC 10021 specifies the procedures performed by MTAs to ensure the correct distributed operation of the MTS.

Annex A provides a reference definition of the MTS object identifiers cited in the ASN.1 modules in the body of this part of ISO/IEC 10021.

Annex B provides a reference definition of the upper bounds of the size constraints imposed upon variable length data types defined in ASN.1 modules in CCITT Recommendation X.411.

Annex C identifies the technical differences between the ISO/IEC and CCITT versions of CCITT Recommendation X.411 and this part of ISO/IEC 10021.

Annex D provides an index to this part of ISO/IEC 10021, categorized into: definitions of the MTS parameters; Abbreviations; Terms; ASN.1 modules; ASN.1 macros; ASN.1 types; and ASN.1 values.