ISO/TS 20684-5:2022

Intelligent transport systems — Roadside modules SNMP data interface — Part 5: Logs

Field devices are a key component in intelligent transport systems (ITS). Field devices include traffic signals, message signs, weather stations, traffic sensors, roadside equipment for connected ITS (C-ITS) environments, etc. Field devices often need to exchange information with other external entities (managers). Field devices can be quite complex, necessitating the standardization of many data concepts for exchange. As such, the ISO 20684 series is divided several individual parts. This document specifies the user needs, requirements and design elements that are used to record timestamped information in a log for later retrieval. This allows a manager to determine the state of a particular object instance nearly simultaneously when the trigger action occurs without frequent polling. NOTE 1 There are similarities between certain portions of NTCIP 1103. NOTE 2 ISO 20684-1 provides additional details about how the ISO 20684 series relates to the overall ITS architecture.

Systèmes de transport intelligents — Interface de données SNMP pour les modules en bord de route — Partie 5: Journal d'événements

General Information

• Status: Published
• Publication Date: 02-Oct-2022
• ICS: 03.220.20 - Road transport
• ICS: 35.240.60 - IT applications in transport
• Technical Committee: ISO/TC 204 - Intelligent transport systems
• Drafting Committee: ISO/TC 204/WG 9 - Integrated transport information, management and control
• Current Stage: 6060 - International Standard published
• Start Date: 03-Oct-2022
• Due Date: 28-Feb-2023
• Completion Date: 03-Oct-2022

Standards Content (Sample)

TECHNICAL ISO/TS
SPECIFICATION 20684-5
First edition
2022-10
Intelligent transport systems —
Roadside modules SNMP data
interface —
Part 5:
Logs
Systèmes de transport intelligents — Interface de données SNMP pour
les modules en bord de route —
Partie 5: Journal d'événements
Reference number
ISO/TS 20684-5:2022(E)
© ISO 2022

---------------------- Page: 1 ----------------------
ISO/TS 20684-5:2022(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2022
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii
  © ISO 2022 – All rights reserved

---------------------- Page: 2 ----------------------
ISO/TS 20684-5:2022(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Conformance . 2
5 User needs . 3
5.1 Log user-defined exceptions . 3
5.1.1 Log user-defined exceptions user need . 3
5.1.2 Log user-defined exception design overview . 3
5.1.3 Graphical relationships. 3
6 Requirements . 4
6.1 Log . 4
6.1.1 Log definition . 4
6.1.2 Log data exchange requirements . 5
6.1.3 Log capability requirements . 5
6.2 Log event factory . 5
6.2.1 Log event factory definition . 5
6.2.2 Log event factory data exchange requirements . 5
6.3 Log manager . 6
6.3.1 Log manager definition . 6
6.3.2 Log management data exchange requirements . 6
6.3.3 Log management capability requirements . 7
7 Dialogues . 7
7.1 Clear old events from a log . 7
8 Security vulnerabilities . 7
Annex A (normative) Management information base (MIB) . 8
Annex B (normative) Requirements traceability matrix (RTM) .19
Bibliography .22
iii
© ISO 2022 – All rights reserved

---------------------- Page: 3 ----------------------
ISO/TS 20684-5:2022(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to
the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see
www.iso.org/iso/foreword.html.
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 2022 – All rights reserved

---------------------- Page: 4 ----------------------
ISO/TS 20684-5:2022(E)
Introduction
0.1  Background
The need for standardized communication with ITS field devices is growing around the world.
Several countries have adopted Simple Network Management Protocol (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 ISO 20684 series may be
used with any 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) the conformance requirements for this document (Clause 4);
b) a set of user needs for user-defined trigger conditions that can “fire” to initiate actions (Clause 5);
c) a set of detailed requirements for the identified user needs (Clause 6);
d) custom dialogues for the logging feature (Clause 7);
e) security considerations for the information defined in this document (Clause 8);
f) the management information bases that define the data for the defined requirements (Annex A);
g) the requirements traceability matrix (RTM) that traces the requirements to the design elements
(Annex B).
v
© ISO 2022 – All rights reserved

---------------------- Page: 5 ----------------------
TECHNICAL SPECIFICATION ISO/TS 20684-5:2022(E)
Intelligent transport systems — Roadside modules SNMP
data interface —
Part 5:
Logs
1 Scope
Field devices are a key component in intelligent transport systems (ITS). Field devices include traffic
signals, message signs, weather stations, traffic sensors, roadside equipment for connected ITS (C-ITS)
environments, etc.
Field devices often need to exchange information with other external entities (managers). Field devices
can be quite complex, necessitating the standardization of many data concepts for exchange. As such,
the ISO 20684 series is divided several individual parts.
This document specifies the user needs, requirements and design elements that are used to record
timestamped information in a log for later retrieval. This allows a manager to determine the state of
a particular object instance nearly simultaneously when the trigger action occurs without frequent
polling.
NOTE 1 There are similarities between certain portions of NTCIP 1103.
NOTE 2 ISO 20684-1 provides additional details about how the ISO 20684 series relates to the overall ITS
architecture.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 20684-1:2021, Intelligent transport systems — Roadside modules SNMP data interface — Part 1:
Overview
ISO/TS 20684-7, Intelligent transport systems – Roadside modules SNMP data interface – Part 7: Support
features
IETF RFC 2578, Structure of Management Information Version 2 (SMIv2), April 1999.
IETF RFC 2579, Textual Conventions for SMIv2, April 1999.
IETF RFC 2580, Conformance Statements for SMIv2, April 1999.
IETF RFC 3411, An Architecture for Describing Simple Network Management Protocol (SNMP) Management
Frameworks, December 2002.
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 20684-1 apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
1
© ISO 2022 – All rights reserved

---------------------- Page: 6 ----------------------
ISO/TS 20684-5:2022(E)
— IEC Electropedia: available at https:// www .electropedia .org/
4 Conformance
This clause follows the rules defined in ISO 20684-1. Table 1 traces each user need to a set of software
features. Table 2 traces each feature to a set of requirements. For a full understanding of these tables
and codes, see ISO 20684-1.
Table 1 — User need and feature conformance
Need Requirement Conformance
5.1: Log user-defined exceptions M
6.1: Log M
6.3: Log manager M
20684-7 6.2: UTC clock M
20684-7 6.4: Object group O
Table 2 — Requirement conformance
Feature Requirement Conformance
6.1: Log
6.1.2.1: Determine log capabilities M
6.1.2.2: Configure global logging limits M
6.1.2.3: Verify global logging configuration M
6.1.2.4: Retrieve logged event M
6.1.3.1: Maximum data size M
6.2: Log event factory
6.2.2.1: Configure a log event factory M
6.2.2.2: Verify configuration of log event factory M
6.2.2.3: Toggle log event factory M
6.2.2.4: Delete log event factory M
6.3: Log manager
6.3.2.1: Configure a log manager M
6.3.2.2: Verify log manager configuration M
6.3.2.3: Retrieve log manager statistics M
6.3.2.4: Retrieve log manager summary statistics M
6.3.2.5: Retrieve log manager status M
6.3.2.6: Toggle a log manager M
6.3.2.7: Clear old events from log M
6.3.2.8: Clear all logs M
6.3.2.9: Delete a log manager M
6.3.2.10: Delete all log managers of an owner M
6.3.3.1: Latency of event logging M
2
  © ISO 2022 – All rights reserved

---------------------- Page: 7 ----------------------
ISO/TS 20684-5:2022(E)
5 User needs
5.1 Log user-defined exceptions
5.1.1 Log user-defined exceptions user need
A manager needs to be able to configure a field device to log events for later retrieval. This user need
allows a manager to detect transient conditions that can potentially occur between successive polls as
well as capturing accurate timestamps of when different events occurred. A manager can potentially
need to manage multiple types of events separately and multiple managers can wish to monitor the
same or different events.
EXAMPLE 1 A manager wants the device to record the number of vehicles counted every 15 min so that the
manager can retrieve the information at the end of each day.
EXAMPLE 2 A manager wants to retrieve diagnostic events (e.g. cabinet door open) separately from
operational events (e.g. a new message on a sign). This can perhaps be due to internal logic or perhaps because
two separate systems communicate with the device.
5.1.2 Log user-defined exception design overview
5.1.2.1 Required features
In the simplest case, the “log user-defined exceptions” user need shall support the following features.
a) A mechanism to initiate the logging action, such as one of the triggering mechanisms specified in
ISO/TS 20684-3.
b) A log event factory, as defined by this document, which defines details about the event to be created
when the logging action is initiated as well as the log in which it will be stored.
3. A log manager, as defined by this document, which allows for the management of each log.
4. A log, as defined by this document, which stores the events created by the log event factory.
5. UTC clock, as specified by ISO/TS 20684-7, which is used to timestamp entries in the log.
5.1.2.2 Optional object group feature
An implementation can support the object group feature, as specified by ISO/TS 20684-7, which can be
used to define a group of multiple object instances to be stored within a log entry as a single field.
5.1.3 Graphical relationships
The relationships among these features are depicted in Figure 1.
3
© ISO 2022 – All rights reserved

---------------------- Page: 8 ----------------------
ISO/TS 20684-5:2022(E)
Figure 1 — Conceptual overview of logging
When a trigger (defined in ISO/TS 20684-3) fires, it calls an action (ISO/TS 20684-3), which may direct
the call to a LogEventFactory. When called, the LogEventFactory captures a defined object value from
the device and records this in a new entry in the identified log based on configured parameters.
While the log entry only records a single object instance value, the object instance can potentially be an
instance of fdObjectGroupCurrentValue (ISO/TS 20684-7), which can contain multiple object instance
values packaged in an efficient manner.
The log can be managed (e.g. fully or partially cleared) using the LogManager. The LogManager also
reports statistics for the log.
6 Requirements
6.1 Log
6.1.1 Log definition
A log is a store of event information for later retrieval.
A log manager creates a log entry when it is called (e.g. by a properly configured action as per
ISO/TS 20684-3). The event entry includes a timestamp of the event and the current value of a specified
object instance.
4
  © ISO 2022 – All rights reserved

---------------------- Page: 9 ----------------------
ISO/TS 20684-5:2022(E)
6.1.2 Log data exchange requirements
6.1.2.1 Determine log capabilities
The field device shall allow the manager to determine the maximum size for the value that can be logged
for each entry and the maximum latency of log entries.
6.1.2.2 Configure global logging limits
The field device shall allow a manager to configure global limits for the log, including the maximum size
of stored data, the maximum number of events, and the maximum age of events.
6.1.2.3 Verify global logging configuration
The field device shall allow a manager to retrieve the configuration of the global logging parameters.
6.1.2.4 Retrieve logged event
The field device shall allow a manager to retrieve a log entry.
6.1.3 Log capability requirements
6.1.3.1 Maximum data size
The log shall be able to store data values of at least 400 octets for each log entry.
6.2 Log event factory
6.2.1 Log event factory definition
The log event factory creates new LogEntries when called from an external process, such as the
fdActionTable, as defined in ISO/TS 20684-3.
6.2.2 Log event factory data exchange requirements
6.2.2.1 Configure a log event factory
The field device shall allow a manager to configure a log event factory by specifying the object instance
whose value should be recorded and the log in which the value should be stored.
6.2.2.2 Verify configuration of log event factory
The field device shall allow a manager to determine the configuration of a log event factory.
6.2.2.3 Toggle log event factory
The field device shall allow a manager to toggle the enabled status of a log event factory.
6.2.2.4 Delete log event factory
The field device shall allow a manager to delete a log event factory.
5
© ISO 2022 – All rights reserved

---------------------- Page: 10 ----------------------
ISO/TS 20684-5:2022(E)
6.3 Log manager
6.3.1 Log manager definition
A log manager is responsible for entering events into its associated log when called by logic (e.g.
ISO/TS 20684-3) and ensuring that the log does not grow beyond its designated size.
6.3.2 Log management data exchange requirements
6.3.2.1 Configure a log manager
The field device shall allow a manager to configure a log manager by specifying its:
a) description;
b) maximum number of entries;
c) maximum storage size; and
d) storage type.
6.3.2.2 Verify log manager configuration
The field device shall allow a manager to retrieve the configuration of a log manager.
6.3.2.3 Retrieve log manager statistics
The field device shall allow a manager to retrieve:
a) the number of events that have been logged in a specific log; and
b) the number of event entries that have been bumped for a specific log.
6.3.2.4 Retrieve log manager summary statistics
The field device shall allow a manager to retrieve:
a) the total number of events that have been logged in all logs; and
b) the total number of event entries that have been bumped for all logs.
6.3.2.5 Retrieve log manager status
The field device shall allow a manager to retrieve the status of each log manager.
6.3.2.6 Toggle a log manager
The field device shall allow a manager to toggle a log manager on and off.
6.3.2.7 Clear old events from log
The field device shall allow a manager to direct a log manager to clear old events from a specific log.
6.3.2.8 Clear all logs
The field device shall allow a manager to clear all entries in all logs.
6
  © ISO 2022 – All rights reserved

---------------------- Page: 11 ----------------------
ISO/TS 20684-5:2022(E)
6.3.2.9 Delete a log manager
The field device shall allow a manager to delete a log manager.
6.3.2.10 Delete all log managers of an owner
The field device shall allow a manager to delete all log managers owned by a specific owner.
6.3.3 Log management capability requirements
6.3.3.1 Latency of event logging
The field device shall enter the notification into the log within 1,0 seconds of the notification being
created, unless otherwise specified.
7 Dialogues
7.1 Clear old events from a log
This dialogue shall be initiated by the manager using logic that is implementation specific. The dialogue
shall be as follows.
a) The manager shall determine the time before which all log entries should be deleted for a specific
log.
b) The manager shall set the value of fdLogManagerClearTiime.x.y and fdLogManagerClearDate.x.y
to indicate the desired time, where "x" indicates the fdLogManagerOwner and "y" indicates the
fdLogManagerName.
c) The device shall delete entries for the indicated log (i.e. for the indicated log owner and log name)
older than the indicated date and time and respond to the request as per the rules of SNMP.
8 Security vulnerabilities
There are data elements defined in this document with a MAX-ACCESS clause of read-write and/or
read-create. These and other data elements are sensitive and need to be protected from malicious and
inadvertent manipulation and/or disclosure. The support for requests in a non-secure environment
without proper protection can have a negative effect on network operations. A sampling of the
vulnerabilities includes:
a) the ability to change when events are logged;
b) the ability to delete logs;
c) the ability to create additional log entries that consume resources intended for other purposes; and
d) the ability to monitor current configurations.
To overcome these vulnerabilities, it is highly recommended that SNMPv3 with TLS support, as defined
in RFC 6353, is used to exchange the data.
7
© ISO 2022 – All rights reserved

---------------------- Page: 12 ----------------------
ISO/TS 20684-5:2022(E)
Annex A
(normative)

Management information base (MIB)
This annex provides definitions which it is useful to import into other management information base
(MIB) modules of this document.
A.1 Log MIB
-- *****************************************************************************
-- A.1.1 Log Header
-- *****************************************************************************

-- ASN1START
LOG-MIB DEFINITIONS ::= BEGIN
IMPORTS

MODULE-IDENTITY, OBJECT-TYPE, OBJECT-IDENTITY, Integer32, Unsigned32, Counter32
                            FROM SNMPv2-SMI
                             -- RFC 2578

TruthValue, StorageType, RowStatus
                            FROM SNMPv2-TC
                             -- RFC 2579

MODULE-COMPLIANCE, OBJECT-GROUP
                            FROM SNMPv2-CONF
                             -- RFC 2580

SnmpAdminString
                            FROM SNMP-FRAMEWORK-MIB
                             -- RFC 3411

ITSDailyTimeStamp, ITSDateStamp, ITSUnsigned8, ITSOerString, fieldDevice,
iso20684p5
                            FROM FIELD-DEVICE-TC-MIB
                             -- ISO 20684-1 Annex A

;
fdLogMIB MODULE-IDENTITY
 LAST-UPDATED "202002132330Z"
 ORGANIZATION "ISO TC 204 WG 9"
 CONTACT-INFO
  "name: Kenneth Vaughn
  phone: [phone]
  email: [e-mail]
  postal: 6606 FM 1488 RD STE 148-503
      Magnolia, TX 77354
       USA"
 DESCRIPTION
  "This MIB defines a mechanism by which a manager can configure a device to
  record information about events in a log for later retrieval."

 REVISION "202002132330Z"
 DESCRIPTION
  "Initial revision of the document as proposed for CD ballot."

 ::= {iso20684p5 1}


-- *****************************************************************************
-- A.1.2 Node Definitions
8
  © ISO 2022 – All rights reserved

---------------------- Page: 13 ----------------------
ISO/TS 20684-5:2022(E)
-- *****************************************************************************

fdLogConformance OBJECT-IDENTITY
 STATUS   current
 DESCRIPTION
  "A node containing conformance statements related to the fdLogMIB, as
  defined in ISO/TS 20684-7."
 ::= {fdLogMIB 2}

fdLogCompliances OBJECT-IDENTITY
 STATUS   current
 DESCRIPTION
  "A node for compliance statements for the fdLogMIB."
 ::= {fdLogConformance 1}

fdLogGroups OBJECT-IDENTITY
 STATUS   current
 DESCRIPTION
  "A node for group definitions related to fdLogMIB."
 ::= {fdLogConformance 2}

fdLog OBJECT-IDENTITY
 STATUS   current
 DESCRIPTION
  "A node defining management information related to the field device's Log."
 ::= {fieldDevice 11}

-- *****************************************************************************
-- A.1.3 Objects
-- *****************************************************************************

fdLogsRecordingLatency OBJECT-TYPE
 SYNTAX   Unsigned32
  UNITS   "milliseconds"
 MAX-ACCESS read-only
 STATUS   current
 DESCRIPTION
  "The maximum latency between retrieving an object value and it appearing in
  the log."
 ::= {fdLog 1}

fdLogsMaxVariableSize OBJECT-TYPE
 SYNTAX   Unsigned32
  UNITS   "octets"
 MAX-ACCESS read-only
 STATUS   current
 DESCRIPTION
  "The maximum size for any variable value that can be recorded in the log."
 ::= {fdLog 2}

fdLogsGlobalSizeLimit OBJECT-TYPE
 SYNTAX   Unsigned32
  UNITS   "octets"
 MAX-ACCESS read-write
 STATUS   current
 DESCRIPTION
  "The maximum storage space for variable values allocated for all logs
  within the field device. Any log entry that would cause the global size to
  exceed this limit will cause the log that is recording the log entry to
  delete its oldest entries until the new entry can be added without
  exceeding this limit. If the log is still not able to record the event
  after clearing all other entries, the new entry will also be bumped without
  being recorded."
 ::= {fdLog 3}

fdLogsGlobalEntryLimit OBJECT-TYPE
 SYNTAX   Unsigned32
 MAX-ACCESS read-write
 STATUS   current
 DESCRIPTION
  "The maximum number of log entries allowed for any log. This is designed
9
© ISO 2022 – All rights reserved

---------------------- Page: 14 ----------------------
ISO/TS 20684-5:2022(E)
  to allow the system administrator to control the size of logs of other
  managers."
 ::= {fdLog 4}

fdLogsGlobalAgeOut OBJECT-TYPE
 SYNTAX   Unsigned32
  UNITS   "seconds"
 MAX-ACCESS read-write
 STATUS   current
 DESCRIPTION
  "The maximum age, in seconds, for any log entry before it is automatically
  deleted."
 ::= {fdLog 5}

fdLogsTotalLogged OBJECT-TYPE
 SYNTAX   Counter32
 MAX-ACCESS read-only
 STATUS   current
 DESCRIPTION
  "The number of events that have been created across all logs."
 ::= {fdLog 6}

fdLogsTotalBumped OBJECT-TYPE
 SYNTAX   Counter32
 MAX-ACCESS read-only
 STATUS   current
 DESCRIPTION
  "The number of log entries that have been
...