ISO/TS 20684-6:2022

Overview

ISO/TS 20684-6:2022 - "Intelligent transport systems - Roadside modules SNMP data interface - Part 6: Commands" defines how ITS field devices can be configured to issue SNMP Set-requests in response to trigger conditions. The technical specification describes user needs, requirements and design elements for a command factory that generates SNMP commands (SET) when a configured trigger fires. It is intended for roadside modules such as traffic signals, dynamic message signs, weather stations, sensors and other field devices that must react autonomously to field conditions.

Key Topics

• Trigger‑based commands: Enables a field manager to automatically send commands when user‑defined exceptions occur (for example, display a warning message when ice is detected).
• Command factory: Central design element that generates SET requests to a target agent. Includes configuration, verification, status, statistics, toggle and delete operations.
• SNMP target & parameters: Uses SNMP target definitions and parameters (as referenced in ISO/TS 20684‑7 and RFC 3413) to identify destination agents and communication settings.
• MIB definitions: Annex A provides Management Information Base (MIB) entries for command functionality to be used with SNMP.
• Data size requirement: Field devices shall support a variable binding list of at least 64 octets per command.
• Conformance & traceability: Clauses include conformance rules and a Requirements Traceability Matrix (Annex B) mapping user needs to features and requirements.
• Security considerations: Identifies vulnerabilities (e.g., unauthorized creation, deletion or modification of commands) and strongly recommends SNMPv3 with TLS (RFC 6353) or equivalent protections.

Applications

ISO/TS 20684-6 is practical for:

• Traffic management centres and ITS operators who need automated local responses to events without constant central supervision.
• Field device manufacturers designing SNMP-enabled roadside modules and MIBs compatible with the ISO 20684 series.
• Systems integrators and consultants writing procurement specifications for open, non‑proprietary ITS deployments.
• C-ITS deployments where roadside equipment must send commands to other devices or to itself based on field triggers.

Benefits include reduced operator load, faster local response to incidents, improved maintainability and open procurement options for interoperable ITS components.

Related Standards

• ISO/TS 20684-1:2021 - Overview and relation to ITS architecture
• ISO/TS 20684-7 - SNMP target and parameters (complements Part 6)
• IETF RFC 3411 / RFC 3413 - SNMP architecture and target MIBs
• RFC 6353 - SNMP over TLS (recommended for secure exchanges)

Keywords: ISO/TS 20684-6:2022, Intelligent Transport Systems, SNMP, command factory, roadside modules, trigger-based commands, MIB, SNMPv3, ITS field devices.