ISO/IEC 10026-2:1998

Overview

ISO/IEC 10026-2:1998 defines the OSI TP (Open Systems Interconnection Transaction Processing) Service for distributed transaction processing in OSI environments. As Part 2 of the ISO/IEC 10026 series, this standard describes the service-level behaviour, service primitives and functional units that enable coordinated transactions, reliable data transfer and commitment across distributed systems. It is technically aligned with ITU‑T Recommendation X.861.

Key topics

• Functional units and dialogue types: The standard decomposes the OSI TP service into functional units (Dialogue, Shared Control, Polarized Control, Handshake, commitment-related units) and explains how combinations produce different dialogue types.
• Service primitives and parameters: A comprehensive set of OSI TP service primitives (e.g., TP-BEGIN-DIALOGUE, TP-END-DIALOGUE, TP-DATA, TP-U-ERROR, TP-P-ABORT) and their parameters are specified for controlling transaction interactions and signalling.
• Data transfer model: TP-DATA and related primitives describe the modelling of reliable data transfer within a transaction dialogue.
• Control and coordination: Services for grant/request control, handshake operations (TP-HANDSHAKE), and polarised/shared control patterns manage access and sequencing between distributed participants.
• Commitment-related services: Primitive definitions and sequences for transaction lifecycle and outcome coordination are provided - including TP-PREPARE, TP-COMMIT, TP-ROLLBACK, TP-ONE-PHASE, TP-READ-ONLY, TP-HEURISTIC-REPORT and completion/rollback notifications - supporting coordinated commit/abort processing across nodes.
• Service state and contingencies: Annexes and service state tables describe dialogue states, node crash handling, keys and contingency behaviours to ensure predictable service semantics.

Applications

ISO/IEC 10026-2 is practical for:

• Middleware and transaction monitor vendors implementing TP-aware services or OSI-compatible transaction layers.
• System architects and protocol designers building distributed transaction systems, remote procedure frameworks, or enterprise transaction middleware that require explicit dialogue, control and commit semantics.
• Database and distributed application engineers needing standardized behaviour for cross-node transaction coordination, error reporting and recovery.
• Telecommunications and legacy OSI environments where adherence to OSI transaction processing models and ITU‑T alignment (X.861) is required.

Related standards

• ISO/IEC 10026 (other parts) - the broader Distributed Transaction Processing series.
• ITU‑T Recommendation X.861 - closely aligned technical specification.

Keywords: ISO/IEC 10026-2, OSI TP Service, Distributed Transaction Processing, TP-BEGIN-DIALOGUE, TP-DATA, TP-PREPARE, TP-COMMIT, transaction primitives, OSI transaction standard.