ISO/IEC 10021-2:2003 PDF

Overview

ISO/IEC 10021-2:2003 - Information technology - Message Handling Systems (MHS): Overall architecture (Part 2) - defines the overall architecture of Message Handling Systems (MHS). Aligned with ITU‑T Rec. X.402 (1999), this standard provides an architectural and technical introduction to MHS, presenting abstract models, naming/addressing rules, routing behavior, and how MHS is realized over OSI. Annexes supply supplemental information to help implementers and architects.

Key topics and technical requirements

• Abstract models: Functional, information and operational models describing primary, secondary and tertiary MHS objects such as users, distribution lists, message transfer systems, user agents, message stores, access units, and message transfer agents.
• Transmittal life‑cycle: Steps and roles for message origination, submission, import/export, transfer, delivery, retrieval and receipt; plus transmittal events (splitting, joining, DL expansion, conversion, routing).
• Naming and addressing: Definitions for directory names, OR‑names, attribute lists and character set considerations for addressing users and distribution lists.
• Routing and directory use: How routing of information objects is performed and the ways MHS may use directory services for name resolution and address lookups.
• Configurations: Guidance on configuring MHS to meet functional, physical and organizational requirements - including representative configurations (fully centralized, centralized transfer/storage, fully distributed) and management domains.
• Security model: Security policies, required security services and elements such as origin authentication, secure access management, data confidentiality, data integrity, non‑repudiation, security labelling, and security management. Techniques like double‑enveloping and encoding guidance are described.
• OSI realization: Conventions and ASN.1 usage for defining abstract services and interfacing MHS components over the Open Systems Interconnection framework.

Applications & who uses this standard

ISO/IEC 10021-2:2003 is intended for:

• System architects and designers creating enterprise or inter‑organizational messaging infrastructures.
• Product vendors and implementers building MHS-compliant user agents, transfer agents, message stores or directory integrations.
• Network and security engineers planning routing, addressing schemes and security services for messaging systems.
• Standards bodies and integrators aligning messaging solutions with OSI and ITU‑T recommendations.

Practical uses include designing robust message routing, implementing directory-based addressing, defining security policies for message handling, and choosing an appropriate physical/organizational MHS configuration.

Related standards

• ITU‑T Recommendation X.402 (1999) - referenced directly in ISO/IEC 10021-2:2003.
• Related ISO/IEC MHS parts and OSI/Directory standards referenced within the document for normative integration.