Overview
ISO/IEC 9805-2:1996 (identical to ITU‑T Rec. X.853) provides a Protocol Implementation Conformance Statement (PICS) proforma for the Commitment, Concurrency and Recovery (CCR) protocol defined in ISO/IEC 9805‑1 (ITU‑T X.852). The document defines the structured PICS that implementers must complete to declare which CCR protocol capabilities, options and implementation details are supported. The proforma (Annex A) is intended for use in conformance testing, procurement and interoperability assessment of Open Systems Interconnection (OSI) CCR protocol implementations.
Key topics and requirements
- PICS proforma structure - a self‑contained questionnaire preserving the numbering and ordering of items in Annex A; implementers must complete it when claiming conformance to ISO/IEC 9805‑1.
- Implementation details - sections to uniquely identify the implementation and supplier, and to record implemented amendments/technical corrigenda.
- PICS notation and columns - standardized columns such as PICS number, item reference, status, support and values to ensure consistent reporting.
- CCR protocol elements covered - the proforma references CCR APDUs and message types (e.g., C‑INITIALIZE‑RI/RC, C‑BEGIN‑RI/RC, C‑PREPARE, C‑COMMIT, C‑ROLLBACK, C‑RECOVER) and details of fields such as atomic‑action and branch identifiers and recovery state.
- Multi‑layer dependencies - provisions to declare dependencies on other protocols and layers within the OSI reference model.
- Conformance rules - a conforming PICS must be technically equivalent to the proforma and describe an implementation conformant to ISO/IEC 9805‑1; it aligns with PICS requirements in ITU‑T X.296 / ISO/IEC 9646‑7.
Applications and who uses it
- Protocol implementers and vendors - complete the PICS to document which CCR protocol features and optional behavior are implemented.
- Conformance and interoperability test laboratories - use the proforma as part of formal testing and to validate claimed capabilities during test campaigns.
- Purchasers and procurement teams - compare supplier PICS responses to procurement requirements for systems that require CCR support (transactional coordination, recovery and concurrency control).
- System integrators and QA teams - verify multi‑layer dependencies and required implementation characteristics for reliable distributed transaction management.
Related standards
- ISO/IEC 9805‑1 (ITU‑T X.852) - CCR protocol specification
- ISO/IEC 9804 (ITU‑T X.851) - CCR service definition
- ISO/IEC 9646‑7 (ITU‑T X.296) - PICS and conformance testing methodology
- OSI reference standards (e.g., ITU‑T X.200/X.210) referenced for layering and conventions
Keywords: ISO/IEC 9805‑2, PICS proforma, CCR protocol, Open Systems Interconnection, protocol conformance, ITU‑T X.853, implementation conformance statement, conformance testing, interoperability.