Overview
ISO/IEC 20944-4:2013 - part of the Metadata Registries Interoperability and Bindings (MDR-IB) series - specifies protocol bindings and common protocol provisions for interoperable access to metadata registries (for example, registries based on ISO/IEC 11179). This part defines a conceptual model (data and control), harmonized session services, common data-transfer semantics, and concrete protocol bindings (notably HTTP/1.1 and WebDAV) so that clients and servers can interoperate reliably when exchanging metadata.
Key topics and technical requirements
- Abstract model: separation into a data model (logical structure of transferred information) and a control model (transactions, events, protocol state).
- Participant and connection models: supports client-server, peer-to-peer, publish/subscribe, multicast and broadcast modes depending on underlying transport.
- State models: defined state diagrams for both server and client roles (connect, wait-for-command, process-command, event handling, disconnect).
- Service families:
- Session establishment (e.g., mdrib_connect to create a session handle; connection options are implementation-defined).
- Session parameter services for negotiating options.
- Security services (authentication/authorization abstractions).
- Data transfer and data sharing semantics (common data-transfer semantics across bindings).
- Miscellaneous administration and management services.
- Protocol bindings provided: explicit bindings for HTTP/1.1 and WebDAV with harmonized session semantics for both connection-oriented and connection-less transports.
- Conformance: definition of protocol conformance paradigm, server/client service conformance, and conformance label prefixes.
- Normative references and notation: uses ISO/IEC 13886 notation for service descriptions and references ISO/IEC 20944‑1, ISO/IEC 20944‑2, ISO/IEC 11404, RFC 2616 (HTTP/1.1), and RFC 4918 (WebDAV).
Practical applications and target users
- System architects and integrators building interoperable metadata registry ecosystems.
- Registry implementers and vendors developing MDR servers or client tools that must interoperate across organizations.
- Enterprise metadata managers seeking standardized access patterns for metadata discovery, sharing, and management.
- Developers of web-based registry clients leveraging HTTP/WebDAV bindings for remote metadata operations.
- Use cases include cross-organization metadata exchange, centralized metadata governance, and tooling for ISO/IEC 11179-compliant registries.
Related standards
- ISO/IEC 20944 series (Parts 1–5) - framework, coding bindings, API bindings, profiles
- ISO/IEC 11179 - metadata registry conceptual model
- ISO/IEC 13886 - LIPC notation used for service descriptions
- RFC 2616 (HTTP/1.1) and RFC 4918 (WebDAV) - protocol specifications referenced by the bindings
Keywords: ISO/IEC 20944-4:2013, MDR-IB, metadata registries, protocol bindings, HTTP, WebDAV, metadata interoperability, ISO/IEC 11179, session services, data transfer semantics, conformance.