Overview
ISO/IEC 9576-2:1995 specifies a Protocol Implementation Conformance Statement (PICS) proforma for the Connectionless Presentation protocol defined in ITU‑T Rec. X.236 (ISO/IEC 9576‑1). The document provides the standardized template and guidance-aligned with ITU‑T Rec. X.296 (ISO/IEC 9646‑7)-for declaring implementation support, protocol identification, corrigenda, and conformance statements. It is a practical tool for documenting how an implementation meets the presentation‑layer requirements for connectionless operation.
Key Topics
- PICS proforma for Connectionless Presentation protocol (X.236 / ISO/IEC 9576‑1):
- Structured fields for protocol identification and implemented technical corrigenda.
- A global conformance question to confirm if all mandatory features are implemented.
- Support declarations for UD PPDU (Unidirectional Data Presentation Protocol Data Unit):
- Roles: sender and/or receiver (PCNLS‑UD‑Sdr / PCLNS‑UD‑Rcv) and minimum role support requirements.
- Supported parameters and prerequisites:
- Presentation PDU parameters (protocol version, calling/called selectors, presentation context definitions, user data).
- Session service parameters (calling/called session addresses, Quality of Service).
- Support of syntaxes:
- Declaration tables for supported transfer syntaxes and abstract syntaxes.
- References to ASN.1 and encoding rules (note references to ITU‑T Rec. X.690 / ISO/IEC 8825‑1).
- Fields to state encoding restrictions (definite/indefinite length forms, primitive/constructed encodings).
- PDV (Presentation Data Value) structure limits:
- Places to record restrictions on number and arrangement of PDVs in user data.
Applications
- Implementers and vendors use ISO/IEC 9576‑2:1995 to document which connectionless presentation features and syntaxes their products support for interoperability.
- Conformance test labs and QA teams use the PICS proforma as input for standardized conformance testing and certification.
- System integrators and procurement specialists use completed PICS forms to compare implementations and ensure compatibility at the presentation layer.
- Useful where ASN.1 encoding rules, transfer syntaxes, and presentation context negotiation are relevant.
Related Standards
- ISO/IEC 9576‑1 / ITU‑T Rec. X.236 - Connectionless Presentation protocol (specification).
- ITU‑T Rec. X.296 / ISO/IEC 9646‑7 - PICS guidance for protocol testing and conformance statements.
- ITU‑T Rec. X.690 / ISO/IEC 8825‑1 - ASN.1 Basic Encoding Rules (referenced for transfer syntaxes).
- ITU‑T Rec. X.256 - referenced within the proforma for related guidance.
Keywords: ISO/IEC 9576-2:1995, PICS, Connectionless Presentation protocol, ITU‑T X.236, presentation layer, ASN.1, transfer syntax, PDV, conformance testing.