IEC 62056-8-8:2020

IEC 62056-8-8 ®
Edition 1.0 2020-04
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Electricity metering data exchange – The DLMS/COSEM suite –
Part 8-8: Communication profile for ISO/IEC 14908 series networks

Échange des données de comptage de l'électricité – La suite DLMS/COSEM –
Partie 8-8: Profil de communication pour réseaux de la série ISO/IEC 14908

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IEC 62056-8-8 ®
Edition 1.0 2020-04
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Electricity metering data exchange – The DLMS/COSEM suite –

Part 8-8: Communication profile for ISO/IEC 14908 series networks

Échange des données de comptage de l'électricité – La suite DLMS/COSEM –

Partie 8-8: Profil de communication pour réseaux de la série ISO/IEC 14908

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 17.220; 35.110; 91.140.50 ISBN 978-2-8322-8082-9

– 2 – IEC 62056-8-8:2020  IEC 2020
CONTENTS
FOREWORD . 7
INTRODUCTION . 9
1 Scope . 10
2 Normative references . 10
3 Terms, definitions and abbreviated terms . 11
3.1 Terms and definitions . 11
3.2 Abbreviated terms . 12
4 Targeted communication environments . 13
5 Use of the communication layers for this profile . 13
5.1 Information related to the use of the standard specifying the lower layers . 13
5.2 The structure of the communication profile . 14
5.3 Lower layers and their use . 14
5.3.1 Overview . 14
5.3.2 Physical layer . 15
5.3.3 Data link layer . 15
5.3.4 Network layer . 15
5.3.5 Transport layer . 15
5.4 Service mapping and Adaptation layer . 16
5.4.1 Overview . 16
5.4.2 Adaptation layer . 16
5.5 Registration and connection management . 27
6 Identification and addressing schemes . 27
7 Specific considerations for the application layer services . 28
7.1 Overview. 28
7.2 Application Association establishment and release: ACSE services . 28
7.2.1 Application association establishment . 28
7.2.2 Application association release . 29
7.2.3 COSEM-OPEN and COSEM-RELEASE service parameters . 29
7.3 xDLMS services . 30
7.4 Security mechanisms . 30
7.4.1 DLMS/COSEM security . 30
7.4.2 Adaptation layer security . 30
7.4.3 Lower layers security . 30
7.5 Transferring long application messages . 30
7.6 Media access, bandwidth and timing considerations . 30
7.7 Other considerations . 30
8 Communication configuration and management . 31
9 The COSEM Application Process . 31
10 Additional considerations for the use of this profile . 31
Annex A (informative) Examples . 32
Annex B (normative) Interface classes . 33
B.1 Interface classes . 33
B.1.1 ISO/IEC 14908 Identification . 33
B.1.2 ISO/IEC 14908 Protocol setup . 33
B.1.3 ISO/IEC 14908 Protocol status . 34

B.1.4 ISO/IEC 14908 Diagnostic . 35
B.2 Relation to OBIS . 37
Annex C (informative) Implementation guide and migration path . 38
C.1 General . 38
C.2 Client-server model . 38
C.2.1 General . 38
C.2.2 Clients . 38
C.2.3 Servers . 39
C.2.4 Application associations . 39
C.3 The COSEM objects. 40
C.3.1 COSEM object model. 40
C.3.2 Referencing methods . 41
C.3.3 The object_list . 42
C.3.4 Mandatory COSEM objects . 42
C.3.5 Application specific objects . 42
C.3.6 Utility table objects . 42
Annex D (informative) OSGP-AES-128-PSK security suite . 46
D.1 General . 46
D.2 Background. 47
D.2.1 Overview . 47
D.2.2 System Assumptions . 47
D.2.3 Threat Model . 47
D.2.4 Design goals . 48
D.2.5 Inspiration . 48
D.3 Terms and definition, abbreviated terms and notation . 48
D.3.1 Terms and definitions . 48
D.3.2 Abbreviated terms . 50
D.3.3 Notation . 50
D.3.4 Other conventions . 50
D.4 Cryptographic Primitives . 51
D.4.1 General . 51
D.4.2 CMAC . 51
D.4.3 CCM . 51
D.5 Cryptographic Functions . 52
D.5.1 Overview . 52
D.5.2 OSGP_KDF: Key Derivation Function . 52
D.5.3 OSGP_MAC: Message Authentication Code Function . 52
D.5.4 OSGP_MAC_VERIFY: Message Authentication Code Verification
Function . 53
D.5.5 OSGP_AE/OSGP_AD: Authenticated Encryption/Decryption Function . 53
D.5.6 OSGP_CSPRNG: Cryptographically Secure Pseudo Random Number
Generator . 55
D.6 Keys . 56
D.7 Secure channel initialization . 58
D.7.1 Overview . 58
D.7.2 Secure Channel State (CryptoContext) . 58
D.7.3 Flow . 58
D.7.4 Security Suite Negotiation . 63
D.7.5 LNAP Commissioning . 64

– 4 – IEC 62056-8-8:2020  IEC 2020
D.7.6 Error Handling and Intrusion Detection . 64
D.7.7 Messages . 64
D.8 Secure Channel Communication . 67
D.8.1 General . 67
D.8.2 The General Process . 68
D.8.3 Unicast communication . 69
D.8.4 Broadcast Communication . 73
D.9 Firmware Downloading . 75
D.10 Key Management . 76
D.10.1 Renewing the Short-term, Meter-unique Keys . 76
D.10.2 Renewing the Short-term, Domain-unique Keys . 76
D.10.3 UpdateDomainKeysRequest . 77
D.10.4 UpdateDomainKeysResponse . 77
D.11 Updating the Long-term, Meter-unique Keys . 77
D.11.1 General . 77
D.11.2 Key Validity Periods . 78
D.12 Error Messages . 78
D.12.1 Overview . 78
D.12.2 AuthenticationFailure . 78
D.12.3 SequenceError . 78
D.13 Security considerations . 78
D.13.1 Reasoning . 78
D.13.2 Recommendation and Guidance for Implementers . 81
Annex E (normative) Repeating mechanism . 83
E.1 Overview. 83
E.2 Terms and definitions . 83
E.3 Protocol specification . 84
E.3.1 Overview . 84
E.3.2 Addressing . 84
E.3.3 Service types . 84
E.3.4 Timers . 84
E.3.5 Request flow . 85
E.3.6 Response flow . 85
E.3.7 Authentication. 85
E.3.8 Examples. 86
E.3.9 Broadcast . 87
E.4 Downlink frame format . 87
E.4.1 Overview . 87
E.4.2 Proxy parameters of request frame . 88
E.5 Uplink Frame format . 92
E.5.1 Overview . 92
E.5.2 Proxy success . 92
E.5.3 Repeating Failure . 93
E.5.4 Authentication failure . 93
Annex F (informative) ISO/IEC 14908-3 Registration and monitoring of LNAPs . 94
F.1 Scope . 94
F.2 Terms and definitions . 94
F.3 Metering device lifecycle . 94
F.4 ATM Protocol . 95

F.4.1 General . 95
F.4.2 ATM roles . 95
F.4.3 Automatic discovery. 95
F.4.4 Discovery domain . 96
F.4.5 ATM messages . 96
F.5 Commissioning . 100
F.5.1 Overview . 100
F.5.2 Commissioning operations . 100
Bibliography . 101

Figure 1 – Functional reference architecture . 13
Figure 2 – Structure of the communication profile . 14
Figure 3 – Adaptation layer structure . 17
Figure 4 – Unprotected Adaptation layer PDU structure . 18
Figure 5 – Protected Adaptation layer PDU structure . 19
Figure 6 – Adaptation layer services . 20
Figure 7 – Client and server ADP_DATA services . 24
Figure D.1 – Key hierarchy diagram . 56
Figure D.2 – Secure channel establishment . 59
Figure D.3 – Challenge request . 60
Figure D.4 – Challenge response . 60
Figure D.5 – Commission Request . 61
Figure D.6 – Commission response . 62
Figure D.7 – Crypto context establishment . 67
Figure D.8 – Authenticate encryption mechanism . 68
Figure D.9 – Authenticated decryption . 69
Figure E.1 – Unacknowledged message exchange . 86
Figure E.2 – Request / Response message . 86
Figure E.3 – Error during request transmission . 86
Figure E.4 – Error during response transmission . 87
Figure E.5 – Proxy Repeater proxy message . 87
Figure E.6 – Proxy Agent proxy message format . 87
Figure E.7 – Proxy Target message format . 88
Figure E.8 – Normal ProxyTrailer . 90
Figure E.9 – Alternate Key Proxy Trailer . 90
Figure E.10 – Proxy SICB field structure . 90
Figure E.11 – Alternate Key format . 91
Figure E.12 – ProxySubnetNode Address (Type1) . 92
Figure E.13 – ProxyUniqueNode_ID Address (Type 2) . 92
Figure E.14 – ProxyBroadcast Address (Type 3) . 92
Figure E.15 – ProxySubnetNode Compact Address (Type 5 and 7) . 92
Figure E.16 – ProxyUniqueNodeCompact Address (Type 6) . 92

Table 1 – Control field. 18

– 6 – IEC 62056-8-8:2020  IEC 2020
Table 2 – Client and Server SAP. 28
Table 3 – Application associations and data exchange in the DLMS/COSEM over
ISO/IEC14908 profile . 29
Table C.1 – Pre-established association parameters . 40
Table C.2 – base_name range for tables categories . 43
Table C.3 – base_names for standard tables BT00 to BT79 . 44
Table D.1 – Security logical layers . 46
Table D.2 – Key type and their scope . 57
Table D.3 – Challenge request . 65
Table D.4 – Challenge response . 65
Table D.5 – Commission request . 66
Table D.6 – Commission response structure . 67
Table D.7 – Request message . 70
Table D.8 – response message structure . 70
Table D.9 – Nonce construction . 70
Table D.10 – Associated Data construction . 71
Table D.11 – Broadcast message . 74
Table D.12 – Broadcast nonce . 74
Table D.13 – Broadcast Associated Data . 74
Table D.14 – Update Domain Keys request . 77
Table D.15 – Update Domain Keys response . 77
Table D.16 – AuthenticationFailure message . 78
Table D.17 – SequenceError message . 78
Table D.18 – Example of risks . 82
Table E.1 – ProxyHeader format . 88
Table E.2 – ProxyDetailedAddress format . 89
Table E.3 – ProxyUniformAddress format . 89
Table E.4 – ProxyTx control format . 89
Table E.5 – Address Type values . 90
Table E.6 – Service types . 91
Table E.7 – Mode types . 91
Table E.8 – Repeating success response. 93
Table E.9 – Repeating Failure. 93
Table E.10 – Authentication failure code . 93
Table F.1 – ATM Message header structure . 97
Table F.2 – ATM payloads . 97
Table F.3 – ATM-query-ID request structure . 98
Table F.4 – ATM-query-ID response structure . 98
Table F.5 – ATM-respond-to-query request structure . 99
Table F.6 – ATM respond-to-query response structure . 99
Table F.7 – Flags . 100

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
ELECTRICITY METERING DATA EXCHANGE –
THE DLMS/COSEM SUITE –
Part 8-8: Communication profile for ISO/IEC 14908 series networks

FOREWORD
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8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
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9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of patent
rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 62056-8-8 has been prepared by IEC technical committee 13,
Electrical energy measurement and control.
The text of this International Standard is based on the following documents:
CDV Report on voting
13/1783/CDV 13/1792/RVC
Full information on the voting for the approval of this International Standard can be found in the
report on voting indicated in the above table.
This document has been drafted in accordance with the ISO/IEC Directives, Part 2.
A list of all parts in the IEC 62056 series, published under the general title Electricity metering
data exange – The DLMS/COSEM suite, can be found on the IEC website.

– 8 – IEC 62056-8-8:2020  IEC 2020
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under "http://webstore.iec.ch" in the data related to
the specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct understanding
of its contents. Users should therefore print this document using a colour printer.

INTRODUCTION
The IEC 62056 DLMS/COSEM suite provides specific communication profile standards for
communication media relevant for smart metering.
Such communication profile standards specify how the COSEM data model and the
DLMS/COSEM application layer can be used on the lower communication media-specific
protocol layers.
Communication profile standards refer to communication standards that are part of the
IEC 62056 DLMS/COSEM suite or to any other open communication standard.
This International Standard specifies DLMS/COSEM communication profile using
ISO/IEC 14908‑1:2012, Information technology – Control network protocol – Part 1: Protocol
stack and ISO/IEC 14908‑3:2012, Information technology – Control network protocol – Part 3:
Power line channel specification. It applies for devices installed on the neighbourhood area
network.
It follows the rules defined in IEC 62056‑5‑3:2017, Annex A, and in IEC 62056-1-0, and
IEC TS 62056-1-1 for its structure.

– 10 – IEC 62056-8-8:2020  IEC 2020
ELECTRICITY METERING DATA EXCHANGE –
THE DLMS/COSEM SUITE –
Part 8-8: Communication profile for ISO/IEC 14908 series networks

1 Scope
This part of IEC 62056 describes how the DLMS/COSEM Application layer and the COSEM
object model as specified in IEC 62056‑5‑3:2017, IEC 62056‑6‑1:2017 and IEC 62056‑6‑2:2017
can be used over the lower layers specified in the IEC 14908 series, forming a DLMS/COSEM
ISO/IEC 14908 communication profile.
This document is part of the IEC 62056 series. Its structure follows IEC 62056-1-0 and
IEC TS 62056-1-1.
Annex A (informative) provides examples of representative instances of data exchange.
NOTE This Annex A is included and referenced for consistency with other parts of the IEC 62056 suite, but it is
empty.
Annex B (normative) defines COSEM interface classes and related OBIS codes for setting up
and managing the DLMS/COSEM communication profile for IEC 14908 networks. These
interface classes and OBIS codes will be moved later to IEC 62056-6-2 and IEC 62056-6-1.
Annex C (informative) provides an implementation guide and specifies a migration path from
Utility Tables based applications to DLMS/COSEM based applications.
Annex D (informative) specifies the OSGP-AES-128-PSK security suite for optional use on the
adaptation layer level.
Annex E (normative) specifies the repeating mechanism over the ISO 14908-3 Power Line
Channel network.
Annex F (informative) specifies ISO/IEC 14908-3 Registration and monitoring of LNAPs.
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.
IEC 62056‑5‑3:2017, Electricity metering data exchange – The DLMS/COSEM suite – Part 5‑3:
DLMS/COSEM application layer
IEC 62056‑6‑1:2017, Electricity metering data exchange – The DLMS/COSEM suite – Part 6‑1:
Object Identification System (OBIS)
‑2:
IEC 62056‑6‑2:2017, Electricity metering data exchange – The DLMS/COSEM suite – Part 6
COSEM interface classes
ISO/IEC 14908‑1:2012, Information technology – Control network protocol – Part 1: Protocol
stack
ISO/IEC 14908‑3:2012, Information technology – Control network protocol – Part 3: Power line
channel specification
EN 50065‑1, Signalling on low‑voltage electrical installations in the frequency range 3 kHz to
148,5 kHz – Part 1: General requirements, frequency bands and electromagnetic disturbances
3 Terms, definitions and abbreviated terms
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
NOTE All the messages in this document use the big endian format
3.1 Terms and definitions
3.1.1
domain
logical network that is a unit for addressing
Note 1 to entry: Subnet (see below) and node addresses are assigned by the administrator responsible for the
domain, and they have meaning only in the context of that domain.
Note 2 to entry: All nodes belongs to the same domain to be able to address each other.
3.1.2
node
abstraction for a physical node that represents the highest degree of address resolvability on a
network
Note 1 to entry: A node is identified (addressed) within a subnet by its (logical) node identifier called Node_ID. A
physical node may belong to more than one subnet; when it does, it is assigned one (logical) node number for each
subnet to which it belongs. A physical node may belong to at most two subnets; these subnets are parts of different
domains. A node may also be identified (absolutely) within a network by its Unique_Node_ID which is immutable.
3.1.3
subnet
set of nodes accessible through the same link layer protocol
Note 1 to entry: In a logical address, a subnet is identified by a Subnet_ID.
3.1.4
transaction
sequence of messages that are correlated
Note 1 to entry: For example, a request and the response to the request are all part of a single transaction. A
transaction succeeds when all the expected messages from every node involved in the transaction are received at
least once. A transaction fails if any of the expected messages within the transaction are not received.

– 12 – IEC 62056-8-8:2020  IEC 2020
3.2 Abbreviated terms
Abbreviated term Meaning
AA Application Association
AARE Application Association Response
AARQ Application Association Request
ACSE Association Control Service Element
ADD Automated Device Discovery
AdpPDU Adaptation layer PDU
AL Application layer
AP Application Process
APDU Application Protocol Data Unit
ASE Application Service Element
ATM Automated Topology Management
BPSK Binary Phase Shift Keyed
COSEM Companion Specification of Energy Metering
CRC Cyclic Redundancy Code
CSM
...