1、BSI Standards PublicationBS ISO 15784-2:2015Intelligent transport systems(ITS) Data exchangeinvolving roadside modulescommunicationPart 2: Centre to field devicecommunications using SNMPBS ISO 15784-2:2015 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of ISO 15784-2
2、:2015.The UK participation in its preparation was entrusted to TechnicalCommittee EPL/278, Intelligent transport systems.A list of organizations represented on this committee can beobtained on request to its secretary.This publication does not purport to include all the necessaryprovisions of a cont
3、ract. Users are responsible for its correctapplication. The British Standards Institution 2015.Published by BSI Standards Limited 2015ISBN 978 0 580 70161 0ICS 03.220.20; 35.240.60Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published unde
4、r the authority of theStandards Policy and Strategy Committee on 30 November 2015.Amendments/corrigenda issued since publicationDate T e x t a f f e c t e dBS ISO 15784-2:2015 ISO 2015Intelligent transport systems (ITS) Data exchange involving roadside modules communication Part 2: Centre to field d
5、evice communications using SNMPSystmes intelligents de transport (SIT) change de donnes impliquant la communication de modules en bordure de route Partie 2: Communications par dispositif du centre au terrain en utilisant le protocole simple de gestion de rseau (SNMP)INTERNATIONAL STANDARDISO15784-2F
6、irst edition2015-11-01Reference numberISO 15784-2:2015(E)BS ISO 15784-2:2015ISO 15784-2:2015(E)ii ISO 2015 All rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO 2015, Published in SwitzerlandAll rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized othe
7、rwise 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 ISOs member body in the country of the requester.ISO copyright officeC
8、h. de Blandonnet 8 CP 401CH-1214 Vernier, Geneva, SwitzerlandTel. +41 22 749 01 11Fax +41 22 749 09 47copyrightiso.orgwww.iso.orgBS ISO 15784-2:2015ISO 15784-2:2015(E)Foreword vIntroduction vi1 Scope . 11.1 General . 11.2 Overview 12 Conformance . 23 Normative references 24 Terms and definitions . 3
9、5 Symbols and abbreviated terms . 56 Overview . 66.1 Conventions . 66.1.1 ASN.1 66.1.2 SNMP terminology . 66.1.3 Format . 66.2 ASN.1 modules and MIBs . 66.3 Logical architecture 76.4 Relationship to the OSI model . 77 Requirements 87.1 Overview 87.2 Terminology and architecture . 87.3 Message proces
10、sing and dispatching . 87.3.1 General 87.3.2 Version 1 Message Processing Model 97.3.3 Version 2 Message Processing Model 97.3.4 Version 3 Message Processing Model 97.3.5 STMP Message Processing Model 97.4 Applications 107.4.1 Entity type 107.4.2 Command generator 107.4.3 Command responder .107.4.4
11、Notification originator .107.4.5 Notification receiver 107.4.6 Proxy forwarder 107.5 Security models . 107.5.1 User-based Security Model for SNMP version 2 107.5.2 User-based Security Model for SNMP version 3 107.5.3 Transport Security Model . 117.6 View-based Access Control . 117.7 Protocol operati
12、ons 117.7.1 SNMPv1 . 117.7.2 SNMPv2 . 127.7.3 SNMPv3 . 127.7.4 STMP 127.7.5 Request ID variation 127.8 Transport mappings 127.8.1 UDP over IPv4 .127.8.2 UDP over IPv6 .127.8.3 TCP over IPv4 137.8.4 TCP over IPv6 137.8.5 Secure Transport Model . 137.9 Management Information Base (MIB) . 137.9.1 Agent
13、 MIBs .13 ISO 2015 All rights reserved iiiContents PageBS ISO 15784-2:2015ISO 15784-2:2015(E)7.9.2 Notification originator MIBs . 137.9.3 Proxy forwarder MIBs 147.9.4 STMP MIB 147.9.5 Transport Security Model MIB 147.9.6 Other supported data 147.10 Interoperability . 148 Simple Transportation Manage
14、ment Protocol (STMP) .148.1 General 148.2 Message dispatch, process, and protocol operations 158.2.1 Dispatcher . 158.2.2 Message elements of procedure 158.2.3 STMP message field definitions . 178.2.4 PDU elements of procedure . 188.3 Transport mappings 218.3.1 General. 218.3.2 UDP over IPv4 .218.3.
15、3 UDP over IPv6 .228.3.4 TCP over IPv4 228.3.5 TCP over IPv6 239 Performance .239.1 Overview . 239.2 Default response time 23Annex A (normative) Profile requirements list .25Annex B (normative) STMP ASN.1 module 29Annex C (normative) STMP management information base 32Annex D (informative) Primer fo
16、r protocol 37Annex E (informative) Encoding examples .45Bibliography .48iv ISO 2015 All rights reservedBS ISO 15784-2:2015ISO 15784-2:2015(E)ForewordISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of prepar
17、ing 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 li
18、aison 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 Di
19、rectives, 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
20、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 decl
21、arations 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 on the meaning of ISO specific terms and expressions related to conformity assessment, as well as information a
22、bout ISOs adherence to the WTO principles in the Technical Barriers to Trade (TBT) see the following URL: Foreword - Supplementary informationThe committee responsible for this document is ISO/TC 204, Intelligent transport systems.ISO 15784 consists of the following parts, under the general title In
23、telligent transport systems (ITS) Data exchange involving roadside modules communication: Part 1: General principles and documentation framework of application profiles Part 2: Centre to field device communications using SNMP Part 3: Application profile-data exchange (AP-DATEX)This part of ISO 15784
24、 deals with the use of SNMP based communications between traffic management centres and roadside modules for the purpose of configuring, controlling, and monitoring their operation. ISO 2015 All rights reserved vBS ISO 15784-2:2015ISO 15784-2:2015(E)IntroductionBackgroundThe need for standardized co
25、mmunication with ITS field devices is growing around the world. A number of 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
26、 time, and improved maintainability. This part of ISO 15784 creates a standard for ITS field device communications based on several simple concepts:a) maximize the use of the SNMP standards which are widely used in the management of network devices;b) provide for the transport of data by means of se
27、rial communication, TCP/IP, UDP/IP, and other transport mechanisms used by the Internet community;c) provide security by the various mechanisms used in the Internet community;d) provide data definitions using the MIB format defined by the SNMP community. The MIBs for ITS device information will not
28、be part of this part of ISO 15784 as these MIBs will be application, locale, and jurisdiction specific to meet local needs. However, a basic set of management information common to all implementations of this protocol is included.By using this approach, agencies can specify open procurements and sys
29、tems can be expanded geographically in an open and non-proprietary manner which reduces the costs, speeds the deployment, and simplifies the integration.OverviewSNMP is a collection of well thought-out and well-proven concepts and principles. SNMP employs the sound principles of abstraction and stan
30、dardization. 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
31、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 part of ISO 15784 includes references to four variants of the network management protocol. Three of these are versions of SNMP as defined by the I
32、nternet Engineering Task Force and the fourth is defined in this part of ISO 15784 and is based on work in the U.S.This part of ISO 15784 does not specify any requirements that contradict or cause non-conformance to the base standards.Document approach and layoutThis part of ISO 15784 defines the fo
33、llowing:a) an overview of this part of ISO 15784, including conventions and architecture (Clause 6);b) the major capabilities of this part of ISO 15784 (Clause 7);c) the technical details of STMP (Clause 8);d) performance requirements for entities claiming conformance to this part of ISO 15784 (Clau
34、se 9);e) a protocol requirements list (Annex A);f) the formal ASN.1 module for STMP (Annex B);vi ISO 2015 All rights reservedBS ISO 15784-2:2015ISO 15784-2:2015(E)g) the formal definition of SNMP objects defined by this part of ISO 15784 (Annex C);h) a primer for understanding the protocols defined
35、in this part of ISO 15784 (Annex D);i) example encodings of messages defined in this part of ISO 15784 (Annex E). ISO 2015 All rights reserved viiBS ISO 15784-2:2015BS ISO 15784-2:2015Intelligent transport systems (ITS) Data exchange involving roadside modules communication Part 2: Centre to field d
36、evice communications using SNMP1 Scope1.1 GeneralThis part of ISO 15784 specifies a mechanism to exchange data and messages in the following cases:a) between a traffic management centre(s) and roadside modules for traffic management;b) between roadside modules used for traffic management.The scope o
37、f this part of ISO 15784 does not include the communication between traffic management centre and in-vehicle units, between roadside modules and in-vehicle units, in-vehicle communication, in-cabinet communication, or motion video transmission from a camera or recorded media.This part of ISO 15784 i
38、s complimentary to ISO 15784-3, but uses a different application layer for the information exchanges to configure, control, and monitor the field traffic control roadside modules. Where ISO 15784-3 is based on the DATEX standards, this part of ISO 15784 uses an alternative approach based on SNMP wit
39、h an optional extension for more efficient transmission over low bandwidth media. Both of these standards conform to the application profile requirements set forth in ISO 15784-1.1.2 OverviewThis application profile is suitable for usage when the following conditions apply:a) when the data to be exc
40、hanged can be defined as one or more elements that can be retrieved or stored. The protocol can support a wide variety of devices and has adopted the concept of a management information base (MIB) which identifies the configuration, control, and monitoring parameters for the roadside module. This st
41、andardized approach is commonly used for network management applications for devices such as routers, switches, bridges, and firewalls. It is also used in many countries to control devices such as dynamic message signs;b) when guaranteed, deterministic, real time exchange of data are not critical. S
42、NMP operations are typically fairly fast, but the underlying network can cause delays in delivering messages or even lost messages; thus, the protocol is not appropriate for applications that require reliable sub-second communications;c) for intermittent exchange of any defined data. Normal SNMP ope
43、rations allow messages to be structured by combining any group of elements into a retrieval or storage request;d) for repeated, frequent exchanges of the same message structure (with potentially different values) on even low bandwidth links. This profile supports both an efficient variant of SNMP kn
44、own as STMP which allows the run-time definition of 13 messages that can be repeatedly exchanged as needed with minimal overhead;e) for allowing a roadside module to issue exception reports when special conditions arise. This profile includes the concept of an inform message that allows an agent to
45、notify the manager of special conditions even though the manager did not specifically request the information at the time.INTERNATIONAL STANDARD ISO 15784-2:2015(E) ISO 2015 All rights reserved 1BS ISO 15784-2:2015ISO 15784-2:2015(E)Note that this part of ISO 15784 does not address the data required
46、 for each specific type of ITS device. Subsequent device communications standards are to be developed to identify the functionality of the device and the objects to manage and monitor that functionality. This part of ISO 15784 is similar to NTCIP 2301 that defines the protocols along with the object
47、s required for controlling, operating, monitoring, and diagnosing those protocols. Other standards define device-specific objects. It is anticipated that regions will develop device MIBs that meet their specific needs.This part of ISO 15784 will allow for open systems deployment using devices from m
48、any manufacturers providing a variety of services in a shared network environment. With such open protocols, public MIBs, and conformance to the standards, roadside modules can become interoperable among vendors and a variety of vendors can provide product in a systems environment.2 ConformanceConfo
49、rmance to this part of ISO 15784 is defined in Annex A through the definition of each feature as mandatory, optional, or conditional. Every effort has been made to make these conformance tables consistent with the body of the text, but in the case of a conflict between the Annex and the main body of this part of ISO 15784, Annex A shall take precedence.This part of ISO 15784 explicitly identifies a number of options that an implementation may support. These are options that are likely to be encountered in deployments and are listed in this
