ISO 17987-2:2025

Road vehicles — Local Interconnect Network (LIN) — Part 2: Transport protocol and network layer services

This document specifies a transport protocol and network layer services tailored to meet the requirements of LIN‑based vehicle network systems on local interconnect networks. The protocol specifies an unconfirmed communication. The LIN protocol supports the standardized service primitive interface as specified in ISO 14229-2. This document provides the transport protocol and network layer services to support different application layer implementations such as: — normal communication messages, and — diagnostic communication messages. The transport layer defines transportation of data that is contained in one or more frames. The transport layer messages are transported by diagnostic frames. A standardized API is specified for the transport layer. Use of the transport layer is targeting systems where diagnostics are performed on the backbone bus (e.g. CAN) and where the system builder wants to use the same diagnostic capabilities on the LIN sub-bus clusters. The messages are in fact identical to ones in ISO 15765-2 and the PDUs carrying the messages are very similar. The goals of the transport layer are: — to have low load on commander node, — to provide full (or a subset thereof) diagnostics directly on the responder nodes, and — to target clusters built with powerful LIN nodes (not the mainstream low cost).

Véhicules routiers — Réseau Internet local (LIN) — Partie 2: Protocole de transport et couches de services réseau

General Information

• Status: Published
• Publication Date: 04-Jun-2025
• ICS: 35.240.60 - IT applications in transport
• ICS: 43.040.15 - Car informatics. On board computer systems
• Technical Committee: ISO/TC 22/SC 31 - Data communication
• Drafting Committee: ISO/TC 22/SC 31 - Data communication
• Current Stage: 6060 - International Standard published
• Start Date: 05-Jun-2025
• Due Date: 30-May-2025
• Completion Date: 05-Jun-2025

Relations

• Revises: ISO 17987-2:2016 - Road vehicles — Local Interconnect Network (LIN) — Part 2: Transport protocol and network layer services
• Effective Date: 06-Jun-2022

Standards Content (Sample)

International
Standard
ISO 17987-2
Second edition
Road vehicles — Local Interconnect
2025-06
Network (LIN) —
Part 2:
Transport protocol and network
layer services
Véhicules routiers — Réseau Internet local (LIN) —
Partie 2: Protocole de transport et couches de services réseau
Reference number
© ISO 2025
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Published in Switzerland
ii
Contents Page
Foreword .vi
Introduction .vii
1 Scope . 1
2 Normative references . 2
3 Terms, definitions, symbols and abbreviated terms . 2
3.1 Terms and definitions .2
3.2 Symbols .3
3.3 Abbreviated terms .4
4 Conventions . 5
5 Network management . 5
5.1 Network management general information .5
5.2 LIN node communication state diagram .5
5.3 Wake up .6
5.3.1 Wake up general information .6
5.3.2 Commander generated wake up .6
5.3.3 Responder generated wake up.6
5.4 Go-to-sleep .7
6 Network layer overview . 8
6.1 General .8
6.2 Format description of network layer services .8
6.3 Internal operation of network layer .9
6.4 Service data unit specification .10
6.4.1 General .10
6.4.2 N_AI, address information .10
6.4.3 .11
6.4.4 .11
6.4.5 .11
6.5 Services provided by network layer to higher layers . 12
6.5.1 Specification of network layer service primitives . 12
6.5.2 N_USData.request . 13
6.5.3 N_USData.confirm . 13
6.5.4 N_USData_FF.indication . 13
6.5.5 N_USData.indication .14
7 Transport layer protocol. 14
7.1 Protocol functions .14
7.2 Single frame transmission .14
7.3 Multiple frame transmission . 15
7.4 Transport layer protocol data units .17
7.4.1 Protocol data unit types .17
7.4.2 SF N_PDU .17
7.4.3 FF N_PDU .17
7.4.4 CF N_PDU .17
7.4.5 Protocol data unit field description.17
7.5 Protocol control information specification .18
7.5.1 N_PCI .18
7.5.2 SingleFrame N_PCI parameter definition .19
7.5.3 FirstFrame N_PCI parameter definition. 20
7.5.4 ConsecutiveFrame N_PCI parameter definition . 20
7.6 Network layer timing .21
7.6.1 Timing constraints .21
7.6.2 Network layer timeouts . 25
7.6.3 Network layer error handling . . 25

iii
7.6.4 Unexpected arrival of N_PDU. 26
8 Data link layer usage .27
8.1 General .27
8.2 Data link layer service parameters .27
8.3 Data link layer interface services . 28
8.3.1 L_Data.request . 28
8.3.2 L_Data.confirm . 28
8.3.3 L_Data.indication . 28
8.4 Mapping of the N_PDU fields . 28
8.5 Transport layer PDU structure and communication . 29
8.5.1 PDU structure . 29
8.5.2 Communication.32
9 Diagnostic communication requirements .32
9.1 Definition of diagnostic classes .32
9.1.1 General .32
9.1.2 Diagnostic class I .32
9.1.3 Diagnostic class II .32
9.1.4 Diagnostic class III .
...