Overview
ISO/IEC 9834-5:1991 defines the registration and naming procedures for VT (Virtual Terminal) Control Object Definitions within the OSI (Open Systems Interconnection) framework. The standard specifies the required contents and format of register entries that record VT control object (CO) definitions and assigns unambiguous ASN.1 OBJECT IDENTIFIER names to those definitions. It is part of the ISO/IEC 9834 series that governs OSI Registration Authorities and the International Register for VT Control Objects.
Key topics and requirements
- Scope and purpose
- Records VT Control Object Definitions used with ISO 9041‑1 (Virtual Terminal Basic Class Protocol) and related VT standards.
- Assigns globally unambiguous ASN.1 OBJECT IDENTIFIERs for VT CO definitions.
- Register structure
- The International Register is organized into sub-registers corresponding to major CO classifications: Miscellaneous COs, FEICOs (Field Entry Instruction COs), FEPCOs (Field Entry Pilot COs), RIOs (Reference Information Objects), and TCCOs (Termination Conditions COs).
- Identifier form example: { iso standard 9834 vt-co-def (5) reg(x) y } with reg(x) values defined (e.g., 0=misco, 1=feico, 2=fepco, 3=rio, 4=tcco).
- Content and format of entries
- Annex A (normative) prescribes mandatory headings and fields: sponsoring authority, date, ASN.1 identifier, descriptor, CO parameters, initial CO values, syntax and semantics, update rules, and additional information.
- Entries include CO parameter tables (category, repertoire, size, defaults) and natural‑language semantics for CO contents and updates.
- Governance and availability
- Registration Authority validates technical conformance to this part of ISO/IEC 9834.
- Changes to the International Register follow consensus procedures comparable to those used for International Standards (but do not require final Council approval).
- Register entries shall be made available on request; expected registration activity is low (typically ≤20 per year).
Practical applications and users
- Who uses ISO/IEC 9834-5
- Standards bodies and OSI Registration Authorities allocating ASN.1 OBJECT IDENTIFIERs for VT COs.
- Implementers of Virtual Terminal protocols (ISO 9040 / ISO 9041‑1) who need registered, unambiguous CO identifiers.
- Product developers, interoperability test labs, and system integrators working with VT basic class implementations.
- Why it matters
- Ensures global, unambiguous naming and machine-readable registration of VT control objects, improving interoperability and consistent implementation of VT protocols.
Related standards
- ISO/IEC 8824: ASN.1 (Abstract Syntax Notation One)
- ISO 9040: Virtual Terminal Basic Class Service
- ISO 9041‑1: Virtual Terminal Basic Class Protocol - Part 1
- ISO/IEC 9834‑1: General procedures for OSI Registration Authorities
Keywords: ISO/IEC 9834-5, VT Control Object Definitions, ASN.1 OBJECT IDENTIFIER, Open Systems Interconnection, OSI Registration Authority, Virtual Terminal, register entries.
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