Overview
ISO/IEC 10021-10:1999 - "Information technology - Message Handling Systems (MHS): MHS routing" defines how messages are routed through an X.400-style Message Handling System (MHS). This part of the ISO/IEC 10021 series supplements the abstract Message Transfer System procedures (see ISO/IEC 10021-4 / ITU‑T X.411) and ties routing behaviour to directory information, authentication and routing knowledge acquisition. The standard is a technical specification for implementers of MHS routing, directory schemas and routing decision logic.
Key Topics
- Routing model and operational characteristics - Defines the overall routing model used by Routing-MTAs and routing collectives.
- Directory schema (OR-address-subtree & routing-collective-subtree) - Specifies object classes, attribute types, name forms and examples for storing routing data in directories (including OR-address elements).
- Routing components - Terms and roles for Routing‑MTA, routing-collective, connection-group, MTA information, routing advice and local use tables.
- Routing procedures - Procedures for routing decisions, front‑end amendments, OR‑address subtree reads, local‑delivery evaluation, routing‑knowledge acquisition, MTA bind‑in/out and trace verification.
- Security & authentication principles - High‑level principles for authenticating directory and routing information used in routing decisions.
- ASN.1 and object identifiers - Rules and naming conventions for ASN.1 definitions and Annex A reference OIDs.
- Conformance and examples - Clauses for conformance testing and annexes with practical examples (PRMDs, ISPs, internal ADMD use, profile and connection‑group identifiers).
Applications
ISO/IEC 10021-10 is targeted at:
- Message system implementers and vendors building X.400/MHS Routing‑MTA components and directory-aware mail gateways.
- Enterprise architects and network operators designing large PRMDs (Private Message Delivery Domains) or multi‑domain routing topologies.
- Directory and identity management teams who must integrate OR-address and routing entries into LDAP/X.500 directory services.
- ISPs and service providers offering managed MHS or gateway services between X.400 and other messaging systems.
Practical scenarios covered in annexes include simple and large PRMD deployments, autonomous departmental routing, public access communities and ISP profiles - useful for planning, deployment and interoperability testing.
Related Standards
- ISO/IEC 10021-1 / ITU‑T F.400 (user‑oriented MHS services)
- ISO/IEC 10021-2 / ITU‑T X.402 (MHS architecture)
- ISO/IEC 10021-4 / ITU‑T X.411 (Message Transfer System abstract service)
- ITU‑T X.400 suite (overall MHS/X.400 messaging standards)
Keywords: ISO/IEC 10021-10:1999, MHS routing, Message Handling Systems, X.400, OR-address, Routing‑MTA, routing‑collective, directory schema, connection‑group, routing advice.