IEC 62056-47:2006

INTERNATIONAL IEC
STANDARD 62056-47
First edition
2006-11
Electricity metering –
Data exchange for meter
reading, tariff and load control –
Part 47:
COSEM transport layers for IPv4 networks
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INTERNATIONAL IEC
STANDARD 62056-47
First edition
2006-11
Electricity metering –
Data exchange for meter
reading, tariff and load control –
Part 47:
COSEM transport layers for IPv4 networks
© IEC 2006 ⎯ Copyright - all rights reserved
No part of this publication may be reproduced or utilized in any form or by any means, electronic or
mechanical, including photocopying and microfilm, without permission in writing from the publisher.
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Telephone: +41 22 919 02 11 Telefax: +41 22 919 03 00 E-mail: inmail@iec.ch Web: www.iec.ch
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For price, see current catalogue

– 2 – 62056-47 © IEC:2006(E)
CONTENTS
FOREWORD.3

1 Scope.5
2 Normative references .5
3 Terms, definitions and abbreviations .6
4 Overview .6
5 The COSEM connection-less, UDP-based transport layer.8
5.1 General .8
5.2 Service specification for the COSEM UDP-based transport layer .9
5.3 Protocol specification for the COSEM UDP-based transport layer.12
6 The COSEM connection-oriented, TCP-based transport layer.14
6.1 General .14
6.2 Service specification for the COSEM TCP-based transport layer .15
6.3 Protocol specification for the COSEM TCP-based transport layer .25

Annex A (informative) Converting OSI-style transport layer services to and from RFC-
style TCP function calls .32

Bibliography.38

INDEX .39

Figure 1 – COSEM as a standard Internet application protocol .7
Figure 2 – Transport layers of the COSEM_on_IP profile .8
Figure 3 – Services of the COSEM connection-less, UDP-based transport layer .9
Figure 4 – The wrapper protocol data unit (WPDU) .13
Figure 5 – The COSEM connection-less, UDP-based transport layer PDU (UDP-PDU) .13
Figure 6 – Services of the COSEM connection-oriented, TCP-based transport layer .16
Figure 7 – The TCP packet format .26
Figure 8 – Figure TCP connection establishment .27
Figure 9 – Disconnecting a TCP connection.28
Figure 10 – Data communication using the COSEM TCP-based transport layer .30
Figure 11 – High-level state transition diagram for the wrapper sub-layer .30
Figure A.1 – TCP connection state diagram .32
Figure A.2 – MSC and state transitions for establishing a transport layer and TCP
connection .33
Figure A.3 – MSC and state transitions for closing a transport layer and TCP connection .34
Figure A.4 – Polling the TCP sub-layer for TCP abort indication .35
Figure A.5 – Sending an APDU in three TCP packets .36
Figure A.6 – Receiving the message in several packets.37

Table 1 – Reserved wrapper Port numbers in the UDP-based COSEM profile.14

62056-47 © IEC:2006(E) – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
ELECTRICITY METERING –
DATA EXCHANGE FOR METER READING,
TARIFF AND LOAD CONTROL –
Part 47: COSEM transport layers for IPv4 networks

FOREWORD
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The International Electrotechnical Commission (IEC) draws attention to the fact that it is claimed that compliance
with this International Standard may involve the use of a maintenance service concerning the stack of protocols on
which the present standard IEC 62056-47 is based.
The IEC takes no position concerning the evidence, validity and scope of this maintenance service.
The provider of the maintenance service has assured the IEC that he is willing to provide services under
reasonable and non-discriminatory terms and conditions with applicants throughout the world. In this respect, the
statement of the provider of the maintenance service is registered with the IEC. Information may be obtained from:
DLMS User Association
Geneva / Switzerland
www.dlms.ch
International Standard IEC 62056-47 has been prepared by IEC technical committee 13:
Equipment for electrical energy measurement and load control.
———————
Device Language Message Specification

– 4 – 62056-47 © IEC:2006(E)
The text of this standard is based on the following documents:
FDIS Report on voting
13/1386/FDIS 13/1397/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
The committee has decided that the contents of this publication will remain unchanged until
the maintenance result date indicated on the IEC web site under "http://webstore.iec.ch" in
the data related to the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
A list of all parts of IEC 62056 series, published under the general title Electricity metering –
Data exchange for meter reading, tariff and load control, can be found on the IEC website.
A bilingual version of the publication may be issued at a later date.

62056-47 © IEC:2006(E) – 5 –
ELECTRICITY METERING –
DATA EXCHANGE FOR METER READING,
TARIFF AND LOAD CONTROL –
Part 47: COSEM transport layers for IPv4 networks

1 Scope
This part of IEC 62056 specifies the transport layers for COSEM communication profiles for
use on IPv4 networks.
These communication profiles contain a connection-less and a connection-oriented transport
layer, providing OSI-style services to the service user COSEM application layer. The
connection-less transport layer is based on the Internet standard User Datagram Protocol.
The connection-oriented transport layer is based on the Internet standard Transmission
Control Protocol.
Although the major part of the COSEM transport layers is the UDP and TCP as they are
specified in the relevant Internet standards, they include an additional sub-layer, called
wrapper.
Annex A shows how the OSI-style transport layer services can be converted to and from UDP
and TCP function calls.
2 Normative references
The following referenced documents are indispensable for the application 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.
IEC 60050-300:2001, International Electrotechnical Vocabulary (IEV) – Electrical and
electronic measurements and measuring instruments – Part 311: General terms relating to
measurements − Part 312: General terms relating to electrical measurements − Part 313:
Types of electrical measuring instruments − Part 314: Specific terms according to the type of
instrument.
IEC 62051:1999, Electricity metering – Glossary of terms
IEC 62051-1:2004, Ed.1., Electricity metering – Data exchange for meter reading, tariff and
load control – Glossary of terms – Part 1: Terms related to data exchange with metering
equipment using DLMS/COSEM
IEC 62056-53, Electricity metering – Data exchange for meter reading, tariff and load control
− Part 53: COSEM application layer
IEC 62056-62, Electricity metering – Data exchange for meter reading, tariff and load control
− Part 62: Interface classes
STD0005 – Internet Protocol
Author: J. Postel
Date: September 1981
Also: RFC0791, RFC079
...