ISO 13400-2:2025

Overview - ISO 13400-2:2025 (DoIP Part 2)

ISO 13400-2:2025 defines the transport protocol and network layer services for Diagnostic communication over Internet Protocol (DoIP). It specifies how a client DoIP entity and in-vehicle server(s) communicate over IP using TCP and UDP, covering secured and unsecured sessions. The standard sets requirements for vehicle gateway behaviour, IP address assignment, vehicle discovery and announcement, test equipment (client) capabilities, and mechanisms to detect and maintain diagnostic connections across vehicle states.

Key technical topics and requirements

• Transport and network layer protocols: Use of IP with TCP and UDP for diagnostic message exchange; handling of UDP packets and TCP data streams.
• Vehicle network integration: IP address assignment (e.g., DHCP-related procedures), multiple vehicle handling, and gateway integration into existing vehicle networks.
• Vehicle discovery and announcement: Mechanisms to detect vehicles on a network and establish communication with vehicle gateways and subcomponents.
• Connection management: Rules for connection establishment, concurrent connection attempts, connection maintenance and gateway control.
• Data routing and sub-component access: Transport-level routing to/from electronic control units and modular subcomponents inside the vehicle.
• Error handling and resilience: Handling physical network disconnects and other fault conditions.
• Mandatory vs optional features: The standard distinguishes mandatory features (vehicle network integration, discovery, status retrieval, connection control, routing, error handling) and optional features (DoIP entity status monitoring, Transport Layer Security (TLS), DoIP entity firewall capabilities).
• Test equipment requirements: Requirements for client DoIP entities to detect, establish and verify communication with vehicles.
• Service interface and application layer considerations: Abstract service primitives, timing/communication parameters, and payload types for diagnostic messages.

Practical applications and who uses this standard

ISO 13400-2:2025 is essential for:

• Automotive OEMs and Tier‑1 suppliers implementing DoIP-compliant vehicle gateways and network architectures.
• Diagnostic tool and test equipment manufacturers (client DoIP entities) that need reliable vehicle discovery, connection, and diagnostic data routing.
• Aftermarket service providers and repair shops deploying DoIP-capable diagnostic systems.
• Telematics and connected-vehicle platform developers integrating diagnostic functions over IP.
• Automotive cybersecurity teams implementing optional TLS and firewall capabilities to secure diagnostic channels.
• Conformance and testing labs validating DoIP implementations against mandatory behaviours and error-handling requirements.

Related standards

• ISO 13400 series (other parts) covering DoIP concepts and higher-layer diagnostic protocols.
• Networking standards (IP, TCP, UDP, DHCP, TLS) referenced for transport and security integration.

Keywords: ISO 13400-2:2025, DoIP, Diagnostic communication over IP, transport protocol, network layer services, vehicle gateway, TCP, UDP, TLS, DHCP, vehicle discovery, vehicle announcement.