ISO 20684-1:2021

INTERNATIONAL ISO
STANDARD 20684-1
First edition
2021-04
Intelligent transport systems —
Roadside modules SNMP data
interface —
Part 1:
Overview
Systèmes de transport intelligents — Interface de données SNMP pour
les modules en bord de route —
Partie 1: Vue d'ensemble
Reference number
©
ISO 2021
© ISO 2021
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ii © ISO 2021 – All rights reserved

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols and abbreviated terms . 2
5 Conformance . 3
6 Conventions . 5
6.1 ASN.1 . 5
6.2 SNMP terminology . 5
7 Architecture . 5
7.1 ITS services . 5
7.2 Physical view . 5
7.3 Communications view . 6
8 User needs . 6
9 Requirements . 7
9.1 Features . 7
9.2 Identifiable requirements. 7
9.3 Structure of data exchange requirements . 7
9.4 Agent performance requirements . 7
10 Dialogues . 8
10.1 General dialogue rules . 8
10.1.1 Manager initiated . 8
10.1.2 Generic and custom dialogues . 8
10.2 Generic dialogues . 8
10.2.1 Get elemental data . 8
10.2.2 Set elemental data . 8
10.2.3 Get tabular data . 8
10.2.4 Set tabular data . 8
10.2.5 Get data column . 9
10.2.6 Get data from dynamic table entry. 9
10.2.7 Get row status of dynamic table entry . 9
10.2.8 Configure entry of a dynamic table . 9
10.2.9 Toggle active status of a dynamic table entry .10
10.2.10 Delete entry from a dynamic table .10
11 Security.11
11.1 Vulnerabilities .11
11.2 Authentication and access control .11
11.3 Encryption .11
11.4 Security recommendation .11
Annex A (normative) Management information base (MIB) .12
Annex B (normative) Requirements traceability matrix (RTM) .19
Bibliography .20
Foreword
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electrotechnical standardization.
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different types of ISO documents should be noted. This document was drafted in accordance with the
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This document was prepared by Technical Committee ISO/TC 204, Intelligent transport systems.
A list of all parts in the ISO 20684 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/ members .html.
iv © ISO 2021 – All rights reserved

Introduction
0.1  Background
The need for standardized communication with ITS field devices is growing around the world. Several
countries have adopted SNMP-based field device communication standards.
There is a growing view and empirical evidence that standardizing this activity will result in improved
ITS performance, reduced cost, reduced deployment time and improved maintainability. The ISO 20684
series extends ISO 15784-2 by defining the management information necessary to monitor, configure
and control features of field devices. The data elements defined in all parts of the ISO 20684 series may
be used with any relevant protocol, but were designed with an expectation that they would be used
with one of the ISO 15784-2 protocols.
By using this approach, agencies can specify open procurements and systems can be expanded
geographically in an open and non-proprietary manner, which reduces costs, speeds up deployment
and simplifies integration.
0.2  Overview
SNMP is a collection of well-thought-out and well-proven concepts and principles. SNMP employs the
sound principles of abstraction and standardization. This has led to SNMP being widely accepted as the
prime choice for communication between management systems and devices on the internet and other
communications networks.
The original implementation of SNMP was used to manage network devices such as routers and
switches. Since then, the use of SNMP has grown into many areas of application on the internet and has
also been used successfully over various serial communications networks.
This document defines management information for ITS field devices following the SNMP conventions.
0.3  Document approach and layout
This document defines:
a) How conformance is defined in subsequent parts of the ISO 20684 series (Clause 5);
b) Terminology and symbols used throughout the various parts of the ISO 20684 series (Clause 3 and
Clause 4);
c) Conventions used throughout the various parts of the ISO 20684 series (Clause 6);
d) The ITS architectural services defined in ISO 14813-1 that are addressed by the ISO 20684 series
(Clause 7);
e) The rules used by other parts of the ISO 20684 series in defining the user needs that drive the
definition of requirements (Clause 8);
f) The rules used by other parts of the ISO 20684 series in defining requirements and constraints
(Clause 9);
g) A set of generic dialogues that are referenced by other parts of the ISO 20684 series (Clause 10);
h) A discussion of security that applies to all devices conforming to the ISO 20684 series (Clause 11);
i) The management information base (MIB) for the features defined by this document (Annex A);
j) A description of the requirements traceability matrix that is provided in each subsequent part of
the ISO 20684 series that traces defined requirements to the required design elements (Annex B).
In addi
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