Overview
ISO/IEC 4396-3:2023 specifies the Common Distributed Application Protocol (CDAP) as part of the Recursive Inter-Network Architecture (RINA) work. CDAP defines an application-level protocol that lets distributed applications communicate at an object level rather than handling low-level serialization and I/O operations. The standard provides the CDAP specification, an overview of its object-oriented messaging model, policy concepts, and notes on context and implementation (DAF, RIB daemon model). Annexes include concrete syntaxes for Google Protocol Buffers (GPB) and JSON.
Key Technical Topics and Requirements
- Object model and object classes: definition of objects, properties, names (ObjName/ObjID), shorthand aliases and object versioning.
- Application entities (AEs) and connections: lifecycle and establishment of application connections, plus the Application Connection State Vector (ACSV) to track state.
- CDAP messages and methods: standardized message structure, opcodes, InvokeID, ObjValue, result/resultReason, scope and filter, and flags to support CREATE, READ, WRITE, START/STOP and related operations.
- Message encoding and concrete syntaxes: specification of encoding approaches and informative annexes for GPB and JSON formats.
- Policies and standardization: a comprehensive policy framework (e.g., authentication, object naming, error handling, ordering, visibility, types and methods) that implementers can adopt or override to ensure interoperability.
- API and validation: notes on the CDAP application programming interface (API) and validation rules for operations and values.
- Contextual guidance: discussion of the RIB daemon model and distributed application patterns within the Recursive Inter-Network Architecture.
Practical Applications and Who Uses This Standard
CDAP is intended for architects, protocol designers, and software engineers building distributed systems that require a uniform object-level communication layer. Typical use cases include:
- Network control and management in telecom and cloud networking where RINA principles are applied.
- Distributed application facilities (DAFs) and middleware that expose object-based interfaces across endpoints.
- IoT platforms and edge systems that benefit from standardized object models and compact encodings (GPB/JSON).
- Interoperability projects requiring policy-driven behavior, authentication, and versioned object schemas.
Adopting ISO/IEC 4396-3:2023 helps reduce the need for bespoke protocols by providing a unifying protocol for object exchange, method invocation, and state management.
Related Standards
- Other parts of the ISO/IEC 4396 series covering the Recursive Inter-Network Architecture (RINA) family.
- Informative annexes in this document: GPB (Google Protocol Buffers) and JSON concrete syntaxes for CDAP message encoding.
Keywords: ISO/IEC 4396-3:2023, CDAP, Common Distributed Application Protocol, RINA, distributed applications, object model, ACSV, message encoding, GPB, JSON, DAF, RIB.