Overview
ISO/IEC 4396-7:2023 specifies the Flow Allocator (FA) for the Recursive Inter‑Network Architecture (RINA). The standard defines the FA service, the behaviour of a Flow Allocator Instance (FAI), and the data structures and interactions needed to create, bind and manage interprocess communication (IPC) flows. It is not a low‑level protocol specification but uses the Common Distributed Application Protocol (CDAP) to sequence interactions and shows how FAI instantiates EFCP (Error and Flow Control Protocol) connections and interacts with naming, policy and resource functions.
Key topics and technical requirements
- Flow lifecycle management: allocation, monitoring and deallocation of flows; FA acts as the manager and spawns FAIs for individual flows.
- Flow object attributes: required fields for CDAP M_CREATE requests such as source/destination naming info, source/destination port‑IDs, source/destination addresses, connection‑ids array, current connection index, QoS parameters (e.g. AverageDataRate, Delay, Jitter), policy lists and parameters, access control, retry limits.
- FA vs FAI roles: FA is the container managing all allocations; an FAI manages a single flow’s end‑to‑end lifecycle and selects policy choices to meet application requests.
- Interaction sequencing: FAI creates EFCP instances before sending CDAP Create Flow Requests to discover destination applications and validate access; responses return success/failure, destination addresses, connection IDs and suggested policies.
- Directory Forwarding Table (DFT): maps application naming information to IPC Process addresses; supports iterative search (next hop or local address) and must provide a default entry to continue lookups.
- Policy framework: FA/FAI behaviour is driven by pluggable policies (e.g., AllocateNotifyPolicy, AllocateRetryPolicy, NewFlowRequestPolicy, SeqRollOverPolicy) and corresponding policy parameters.
- Events and behaviour specification: detailed states, events and behaviours for FA and FAI (see clauses on behaviour, instance behaviour and events).
Applications and who uses it
This standard is targeted at:
- Network architects and designers building RINA‑based systems
- Middleware and IPCP (IPC Process) implementers who must support flow creation, QoS and policy selection
- Firmware and software vendors integrating EFCP and CDAP for distributed messaging
- System integrators and researchers implementing recursive inter‑network solutions or experimental distributed systems
Practical uses include controlled creation of IPC flows with QoS guarantees, name‑based application discovery across DIFs, modular policy selection for flow behaviour, and integration of resource and sequence number management in distributed IPC.
Related standards
- ISO/IEC 4396-1 - Recursive Inter‑Network Architecture: Reference Model (normative reference)
- CDAP and EFCP are referenced as the protocol and transport/control components used in the flow allocation sequence.
Keywords: ISO/IEC 4396-7:2023, Flow Allocator, Recursive Inter‑Network Architecture, FAI, CDAP, EFCP, Directory Forwarding Table, QoS, Allocate_Request, IPC Process, policy-driven flow allocation.