Overview
ISO/IEC 9548-2:1995 - titled Information technology - Open Systems Interconnection - Connectionless Session protocol: Protocol Implementation Conformance Statement (PICS) proforma - provides the official PICS proforma for the connectionless Session protocol defined in ITU‑T Rec. X.235 / ISO/IEC 9548‑1. The document defines a standardized questionnaire-style proforma (Annex A) suppliers must complete to declare which protocol capabilities and options their implementation supports, and it specifies how to record corrigenda, implementation identity and a global statement of conformance.
Key topics and requirements
- PICS proforma structure: A set of items (rows) each with an item number, description, Status and Support fields. The proforma is designed as a questionnaire to capture implementation choices and mandatory capabilities.
- Status and Support semantics: Definitions for entries in the Status column (levels of required support) and allowed Support answers, used to express conformance requirements.
- Prerequisite notation: Mechanism to mark tables or items as applicable only when a predicate is true (e.g., feature dependencies).
- Item numbering and referencing: Rules for uniquely identifying items so they can be referenced from test specifications, predicates and test-suite parameters.
- Instructions for completion: Guidance on filling the proforma, including identification of supplier, implementation details, dates and how to record applied corrigenda.
- Conformance requirements: A conforming PICS must be technically equivalent to the published proforma, preserve numbering/ordering and include information necessary to uniquely identify the supplier and implementation.
- Protocol-specific tables: Includes tables for UD SPDU sender/receiver support, supported parameters and other connectionless Session protocol options.
Applications and who uses it
- Protocol implementers and vendors: Complete the PICS to document which options and features of the connectionless Session protocol are implemented.
- Conformance test laboratories and certification bodies: Use PICS entries to plan and execute conformance tests (per ITU‑T X.296 / ISO/IEC 9646‑7 guidance) and verify test requirements.
- Interoperability engineers and integrators: Compare PICS from multiple products to determine compatibility and integration effort.
- Procurement and compliance teams: Require a completed PICS as part of procurement, evaluation and compliance records.
Related standards
- ITU‑T Rec. X.235 / ISO/IEC 9548‑1 - Connectionless Session protocol: Protocol specification
- ITU‑T Rec. X.296 / ISO/IEC 9646‑7 - Guidance on PICS and conformance testing methodology
- ITU‑T Rec. X.200 / ISO/IEC 7498‑1 - OSI Basic Reference Model
Keywords: ISO/IEC 9548-2, PICS proforma, connectionless Session protocol, X.235, Protocol Implementation Conformance Statement, conformance testing, UD SPDU, OSI.