EN 50173-5:2018

SLOVENSKI STANDARD
01-oktober-2018
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SIST EN 50173-5:2008
SIST EN 50173-5:2008/A1:2011
SIST EN 50173-5:2008/A1:2011/AC:2011
SIST EN 50173-5:2008/A2:2013
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Information technology - Generic cabling systems - Part 5: Data centre spaces
Informationstechnik - Anwendungsneutrale Kommunikationskabelanlagen - Teil 5:
Rechenzentrumsbereiche
Technologies de l'information - Systèmes de câblage générique - Partie 5: Espaces de
centres de traitement de données
Ta slovenski standard je istoveten z: EN 50173-5:2018
ICS:
33.040.50 Vodi, zveze in tokokrogi Lines, connections and
circuits
35.110 Omreževanje Networking
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD EN 50173-5
NORME EUROPÉENNE
EUROPÄISCHE NORM
June 2018
ICS 33.040.50 Supersedes EN 50173-5:2007
English Version
Information technology - Generic cabling systems - Part 5: Data
centre spaces
Technologies de l'information - Systèmes de câblage Informationstechnik - Anwendungsneutrale
générique - Partie 5: Espaces de centres de traitement de Kommunikationskabelanlagen - Teil 5:
données Rechenzentrumsbereiche
This European Standard was approved by CENELEC on 2018-03-19. CENELEC members are bound to comply with the CEN/CENELEC
Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.
Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC
Management Centre or to any CENELEC member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CENELEC member into its own language and notified to the CEN-CENELEC Management Centre has the
same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic,
Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden,
Switzerland, Turkey and the United Kingdom.

European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2018 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN 50173-5:2018 E
Contents Page
European foreword . 5
Introduction . 6
1 Scope and conformance . 9
1.1 Scope . 9
1.2 Conformance . 9
2 Normative references . 10
3 Terms, definitions and abbreviations . 10
3.1 Terms and definitions . 10
3.2 Abbreviations . 12
4 Structure of the generic cabling system in computer room spaces of data centres . 12
4.1 General. 12
4.2 Functional elements . 12
4.3 Structure and hierarchy . 13
4.4 Cabling subsystems . 14
4.4.1 Data centre cabling subsystems . 14
4.4.2 Associated cabling subsystems . 15
4.5 Design objectives . 16
4.5.1 General. 16
4.5.2 Zone distribution cabling . 16
4.5.3 Intermediate distribution cabling . 16
4.5.4 Main distribution cabling . 16
4.5.5 Network access cabling . 16
4.5.6 Tie cabling . 17
4.6 Accommodation of functional elements . 18
4.6.1 General. 18
4.6.2 Equipment Outlets . 18
4.6.3 Distributors . 18
4.6.4 Cables . 18
4.6.5 Local Distribution Points . 18
4.6.6 External Network Interface . 18
4.7 Interfaces . 18
4.7.1 Equipment interfaces and test interfaces . 18
4.7.2 Channels and links . 20
4.8 Dimensioning and configuration . 20
4.8.1 Distributors . 20
4.8.2 Cables . 20
4.8.3 Connecting hardware . 20
4.8.4 Cords. 20
4.8.5 Equipment Outlets and Local Distribution Points . 21
4.8.6 External Network Interface . 21
5 Channel performance in computer room spaces of data centres . 22
5.1 General. 22
5.2 Environmental performance . 23
5.3 Transmission performance. 23
5.3.1 General. 23
5.3.2 Balanced cabling . 23
5.3.3 Optical fibre cabling . 24
6 Reference implementations in computer room spaces of data centres . 24
6.1 General. 24
6.2 Balanced cabling . 24
6.2.1 General. 24
6.2.2 Zone distribution cabling . 24
6.2.3 Intermediate distribution cabling . 29
6.2.4 Main distribution cabling . 30
6.2.5 Network access cabling . 32
6.3 Optical fibre cabling . 34
6.3.1 General. 34
6.3.2 Component choice . 35
6.3.3 Dimensions . 35
7 Cable requirements in computer room spaces of data centres . 35
7.1 General. 35
7.2 Balanced cables of Category 5, 6, 6A, 7, 7A, 8.1 and 8.2. 35
7.3 Optical fibre cables of Category OM3, OM4, OM5, OS1a and OS2 . 35
8 Connecting hardware requirements in computer room spaces of data centres . 35
8.1 General requirements . 35
8.2 Balanced connecting hardware . 36
8.2.1 General requirements . 36
8.2.2 Electrical, mechanical and environmental performance . 36
8.3 Optical fibre connecting hardware . 36
8.3.1 General requirements . 36
8.3.2 Optical, mechanical and environmental performance . 37
9 Requirements for cords and jumpers in computer room spaces of data centres . 37
9.1 Jumpers . 37
9.2 Balanced cords of Category 5, 6, 6A, 7, 7A, 8.1 and 8.2 . 37
9.2.1 General. 37
9.2.2 Additional requirements for certain cords . 37
9.3 Optical fibre cords of Category OM3, OM4, OM5, OS1a and OS2 . 37
Annex A (normative) Link performance limits. 38
A.1 General. 38
A.2 Balanced cabling . 39
A.3 Optical fibre cabling . 39
Annex B (normative) Usage of high density connecting hardware within optical fibre cabling . 40
B.1 General. 40
B.2 Examples of cabling configurations using high density connecting hardware . 40
B.3 Channel performance . 40
Annex C (normative) Combination of balanced cabling links . 43
C.1 General. 43
C.2 Requirements . 43
Bibliography . 44
Figures
Figure 1 — Schematic relationship between the EN 50173 series and other relevant standards . 7
Figure 2 — Structure of generic cabling . 13
Figure 3 — Hierarchical topology of generic cabling . 14
Figure 4 — Examples of cabling implementation to improve reliability . 17
Figure 5 — Example of accommodation of functional elements. 18
Figure 6 — Test and equipment interfaces . 19
Figure 7 — The External Network Interface . 21
Figure 8 — Example of a channel . 22
Figure 9 — Example of a system showing the location of cabling interfaces . 23
Figure 10 — Zone distribution cabling models . 27
Figure 11 — Intermediate distribution cabling model . 29
Figure 12 — Main distribution cabling model. 31
Figure 13 — Network access cabling model . 33
Figure A.1 — Link options . 38
Figure B.1 — Examples of high density connecting hardware within main distribution cabling . 41
Figure B.2 — Examples of high density connecting hardware at the LDP and EO within zone
distribution cabling . 42
Figure C.1 — Examples of combination of different links . 43
Tables
Table 1 — Contextual relationship between EN 50173 series and other standards relevant for
information technology cabling systems . 7
Table 2 — Zone distribution channel equations . 28
Table 3 — Intermediate distribution channel equations . 30
Table 4 — Main distribution channel equations . 32
Table 5 — Network access cabling channel equations . 34
European foreword
This document (EN 50173-5:2018) has been prepared by the Technical Committee CENELEC TC 215
"Electrotechnical aspects of telecommunication equipment".
The following dates are fixed:
• latest date by which this document has (dop) 2019-03-19
to be implemented at national level by
publication of an identical national
standard or by endorsement
• latest date by which the national (dow) 2021-03-19
standards conflicting with this document
have to be withdrawn
This document supersedes EN 50173-5:2007 + A1:2010 + AC:2011 + A2:2012.
The European Standards EN 50173:1995 and EN 50173-1:2002 have been developed to enable the
application-independent cabling to support ICT applications in office premises. Their basic principles,
however, are applicable to other types of applications and in other types of premises.
TC 215 has decided to establish relevant European Standards which address the specific requirements of
these premises. In order to point out the commonalities of these cabling design standards, these EN are
published as individual parts of the series EN 50173, thus also acknowledging that standards users recognize
the designation “EN 50173” as a synonym for generic cabling design.
At the time of publication of this European Standard, series EN 50173 comprises the following standards:
EN 50173-1 Information technology — Generic cabling systems — Part 1: General requirements
EN 50173-2 Information technology — Generic cabling systems — Part 2: Office spaces
EN 50173-3 Information technology — Generic cabling systems — Part 3: Industrial spaces
EN 50173-4 Information technology — Generic cabling systems — Part 4: Homes
EN 50173-5 Information technology — Generic cabling systems — Part 5: Data centre spaces
EN 50173-6 Information technology — Generic cabling systems — Part 6: Distributed building
services
This edition of EN 50173-5:
a) introduces new components 8.1 and 8.2 for balanced cabling to support new channel Classes I and II as
well as optical fibre cabling (OM5) as defined in EN 50173-1:2018;
b) clarifies that the cabling defined in this standard applies to computer rooms in data centres;
c) aligns the document structure across the EN 50173 series and updates the document both technically
and editorially.
Introduction
The importance of cabling infrastructure is similar to that of other fundamental utilities such as water and
energy supply and interruptions to the services provided over that infrastructure can have a serious impact. A
lack of design foresight, the use of inappropriate components, incorrect installation, poor administration or
inadequate support can threaten quality of service and have commercial consequences for all types of users.
This standard specifies generic cabling within computer room spaces in data centre premises, or data centre
spaces within other types of building.
Additionally those premises can include:
— office spaces for which generic cabling is specified in EN 50173-2;
— industrial spaces for which generic cabling is specified in EN 50173-3.
Generic cabling for distributed building services in data centre spaces is specified in EN 50173-6 which
addresses all of the above premises and spaces within them.
Figure 1 and Table 1 show the schematic and contextual relationships between the standards produced by
TC 215 for information technology cabling, namely:
1) this and other parts of the EN 50173 series;
2) installation (EN 50174 series);
3) bonding (EN 50310).
Figure 1 — Schematic relationship between the EN 50173 series and other relevant standards
Table 1 — Contextual relationship between EN 50173 series and other standards relevant for
information technology cabling systems
Building design Generic cabling Specification Installation Operation phase
phase design phase phase phase
EN 50173-2 EN 50174-1
EN 50173-3
Planning phase
EN 50173-4
EN 50174-2
EN 50173-5
EN 50310 EN 50174-3 EN 50174-1
EN 50173-6
EN 50174-2
EN 50310
EN 50174-3
(these ENs
EN 50310
reference general
requirements of
EN 50173-1)
In addition, a number of Technical Reports have been developed to support or extend the application of these
standards, including:
— CLC/TR 50173-99-1, Cabling guidelines in support of 10 GBASE-T;
— CLC/TR 50173-99-2, Information technology — Implementation of BCT applications using cabling in
accordance with EN 50173-4;
— CLC/TR 50173-99-3, Information technology — Generic cabling systems — Part 99-3: Home cabling
infrastructures up to 50 m in length to support simultaneous and non simultaneous provision of
applications.
In addition, a number of cabling design standards have been developed using components of EN 50173-1
(e.g. EN 50098 series and EN 50700).
The generic cabling specified by this standard provides users with:
— an application independent system capable of supporting a wide range of applications in a range of
installation and operating environments;
— a flexible scheme such that modifications are both easy and economical;
— a multi-vendor supply chain within an open market for cabling components.
In addition this standard provides:
a) relevant industry professionals with guidance allowing the accommodation of cabling before specific
requirements are known; i.e. in the initial planning either for construction or refurbishment and for further
deployment as the requirements of areas are defined;
b) industry and standardization bodies with a cabling system which supports current products and provides
a basis for future product development and applications standardization.
Applications addressed in this standard include those developed by the Technical Committees of IEC
(including the subcommittees of ISO/IEC JTC 1) and study groups of ITU-T within the densely connected
environment of data centre spaces.
Physical layer requirements for the applications listed in EN 50173-1:2018, Annex F, have been analysed to
determine their compatibility with the cabling performance specified in this standard and, together with
statistics concerning premises geography from different countries and the models described in Clause 4,
have been used to develop the requirements for cabling components and to stipulate their arrangement into
cabling systems.
As a result, this standard:
a) specifies a structure for generic cabling supporting a wide variety of applications including, but not
restricted to, those in EN 50173-1:2018, Annex F;
b) adopts balanced cabling channel and link Classes EA, F, FA, I and II specified in EN 50173-1;
c) adopts optical fibre cabling channel and link requirements specified in EN 50173-1;
d) adopts component requirements, specified in EN 50173-1, and specifies cabling implementations that
ensures performance of links and of channels meeting the requirements of a specified group (e.g. Class)
of applications.
Life expectancy of generic cabling systems can vary depending on environmental conditions, supported
applications, aging of materials used in cables, and other factors such as access to pathways (campus
pathways are more difficult to access than building pathways).
With appropriate choice of components, generic cabling systems meeting the requirements of this standard
are expected to have a life expectancy of at least ten years.
This document should be read in conjunction with EN 50600-2-4 which describes other aspects of
telecommunications cabling in the computer room and other spaces of data centres.
1 Scope and conformance
1.1 Scope
This standard specifies generic cabling within computer room spaces in data centre premises, or data centre
spaces within other types of building.
It covers balanced cabling and optical fibre cabling.
This standard specifies directly or via reference to EN 50173-1 the:
— structure and minimum configuration for generic cabling within data centre spaces;
— interfaces at the external network interface (ENI) and equipment outlet (EO);
— performance requirements for cabling links and channels;
— implementation requirements and options;
— performance requirements for cabling components;
— conformance requirements and verification procedures.
This standard has taken into account requirements specified in application standards listed in EN 50173-1.
Safety and electromagnetic compatibility (EMC) requirements are outside the scope of this standard and are
covered by other standards and regulations. However, information given in this standard can be of assistance
in meeting these standards and regulations.
1.2 Conformance
For a cabling installation to conform to this standard the following applies.
a) The configuration and structure shall conform to the requirements of Clause 4.
b) Channels shall meet the requirements of Clause 5.
This shall be achieved by one of the following:
1) a channel design and implementation ensuring that the prescribed channel performance of Clause 5
is met;
2) attachment of appropriate components to a permanent link or LDP link design meeting the
prescribed performance class of Annex A. Channel performance shall be ensured where a channel
is created by adding more than one cord to either end of a link meeting the requirements of
Annex A;
3) for E environments, using the reference implementations of Clause 6 and compatible cabling
components conforming to the requirements of Clauses 7, 8 and 9 based upon a statistical
approach of performance modelling.
c) The interfaces to the cabling at the EO and ENI shall conform to the requirements of Clause 8 with
respect to mating interfaces and performance.
d) Connecting hardware at other places in the cabling structure shall meet the performance requirements
specified in Clause 8 independent of the interface used.
e) The requirements of EN 50174 series standards and EN 50310 shall be met.
f) Local regulations, including those concerning safety and EMC, shall be met.
This standard does not specify which tests and sampling levels should be adopted. Test methods to assess
conformance with the channel and link requirements of Clause 5 and Annex A respectively are specified in
EN 50173-1. The test parameters to be measured, the sampling levels and the treatment of measured results
to be applied for a particular installation shall be defined in the installation specification and quality plans for
that installation prepared in accordance with EN 50174-1.
In the absence of the channel, the conformance of the link shall be used to verify conformance with the
standard.
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.
EN 50173-1:2018, Information technology — Generic cabling systems — Part 1: General requirements
EN 50174-1, Information technology — Cabling installation — Part 1: Installation specification and quality
assurance
EN 50174-2, Information technology — Cabling installation — Part 2: Installation planning and practices
inside buildings
EN 50174-3, Information technology — Cabling installation — Part 3: Installation planning and practices
outside buildings
EN 61076-3-106:2006, Connectors for electronic equipment — Product requirements — Part 3-106:
Rectangular connectors — Detail specification for protective housings for use with 8-way shielded and
unshielded connectors for industrial environments incorporating the IEC 60603-7 series interface (IEC 61076-
3-106:2006)
EN 61076-3-110, Connectors for electronic equipment — Product requirements — Part 3-110: Detail
specification for shielded, free and fixed connectors for data transmission with frequencies up to 1 000 MHz
(IEC 61076-3-110)
EN 61754-7-1, Fibre optic interconnecting devices and passive components — Fibre optic connector
interfaces — Part 7-1: Type MPO connector family — One fibre row (IEC 61754-7-1)
EN IEC 61754-7-2, Fibre optic interconnecting devices and passive components — Fibre optic connector
interfaces — Part 7-2: Type MPO connector family — Two fibre rows (IEC 61754-7-2)
EN 61754-20:2012, Fibre optic interconnecting devices and passive components — Fibre optic connector
interfaces — Part 20: Type LC connector family (IEC 61754 20:2012)
3 Terms, definitions and abbreviations
3.1 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 50173-1 and EN 50174-1 and the
following apply.
3.1.1
computer room space
area within the data centre that accommodates the data processing, data storage and telecommunication
equipment that provides the primary function of the data centre
3.1.2
data centre
structure, or group of structures, dedicated to the centralized accommodation, interconnection and operation
of information technology and network telecommunications equipment providing data storage, processing and
transport services together with all the facilities and infrastructures for power distribution and environmental
control together with the necessary levels of resilience and security required to provide the desired service
availability
Note 1 to entry: A structure can consist of multiple buildings and/or spaces with specific functions to support the primary
function.
Note 2 to entry: The boundaries of the structure or space considered the data centre which includes the information and
communication technology equipment and supporting environmental controls can be defined within a larger structure or
building.
[SOURCE: EN 50600-1:2012, 3.1.9, modified – added Note 2 to entry]
3.1.3
equipment outlet
fixed connecting device where the zone distribution cabling terminates and providing the interface to the
equipment cabling
3.1.4
intermediate distribution cable
cable connecting the intermediate distributor to the zone distributor
3.1.5
intermediate distributor
distributor used to make connections between the main distribution cabling subsystem, intermediate
distribution cabling subsystem, network access cabling subsystem and active equipment
3.1.6
local distribution point
connection point in the zone distribution cabling subsystem between a zone distributor and one or more
equipment outlets
3.1.7
local distribution point cable
LDP cable
cable connecting a local distribution point to an equipment outlet
3.1.8
local distribution point link
LDP link
transmission path between a local distribution point and the interface at the other end of the zone distribution
cable including the connecting hardware at each end
3.1.9
main distribution cable
cable connecting the main distributor to the intermediate distributor
3.1.10
main distributor
distributor used to make connections between the main distribution cabling subsystem, network access
cabling subsystem and active equipment
3.1.11
network access cable
cable connecting the external network interface (or other distributors of the EN 50173 series) to the main
distributor, intermediate distributor or zone distributor
3.1.12
zone distribution cable
cable connecting the zone distributor to the equipment outlet(s) or local distribution point(s)
3.1.13
zone distributor
distributor used to make connections between the main distribution cabling subsystem, zone distribution
cabling subsystem, network access cabling subsystem and active equipment
3.2 Abbreviations
For the purposes of this document, the abbreviations of EN 50173-1 and the following apply.
BEF Building entrance facility
ENI External network interface
EO Equipment outlet
ID Intermediate distributor
LDP Local distribution point
MD Main distributor
OE EQP Opto-electronic equipment
ZD Zone distributor
4 Structure of the generic cabling system in computer room spaces of data centres
4.1 General
This clause identifies the functional elements of generic cabling, describes how they are connected together
to form subsystems and identifies the interfaces at which application-specific components are connected to
the generic cabling infrastructure. Channels, created by connecting application-specific cabling components
to the generic cabling, are used to support applications. Applications listed in EN 50173-1:2018, Annex F, are
supported by connecting active equipment at the external network interfaces, equipment outlets and the
distributors.
4.2 Functional elements
This standard specifies the following functional elements and interfaces of generic cabling:
a) external network interface (ENI);
b) network access cable;
c) main distributor (MD);
d) main distribution cable;
e) intermediate distributor (ID) ;
f) intermediate distribution cable;
g) zone distributor (ZD);
h) zone distribution cable;
i) local distribution point (LDP);
j) local distribution point cable (LDP cable);
k) equipment outlet (EO).
Groups of these functional elements are connected together to form cabling subsystems (see 4.3).
4.3 Structure and hierarchy
Generic cabling systems contain up to four types of cabling subsystems: network access, main distribution,
intermediate distribution and zone distribution. Where present and required, distributors of other parts of the
EN 50173 series within the premises can be connected to the generic cabling using the network access
cabling.
The cabling subsystems are connected together to create a generic cabling system with a structure as shown
in Figure 2. The composition of the cabling subsystems is described in 4.4.1. The functional elements of the
cabling subsystems are interconnected to form a basic hierarchical topology as shown in Figure 3.
Where the functions of distributors are combined (see 4.8.1) the cabling subsystems linking them are not
required.
Connections between cabling subsystems are either active, requiring application-specific equipment, or
passive. Connection to application-specific equipment at an MD and ZD adopts an interconnect or a cross-
connect approach (see EN 50173-1). Connection to application-specific equipment at an ENI and EO adopts
an interconnect approach (see EN 50173-1). Passive connections between cabling subsystems adopt either
a cross-connect approach, by way of either patch cords or jumpers, or an interconnect approach.

NOTE The ENI and/or distributors in accordance with EN 50173-1 can also be connected via network access
cabling to an ID or ZD.
Figure 2 — Structure of generic cabling
NOTE Network access cabling is also used to connect distributors of the EN 50173 series, and ENIs, to the ID and/or
ZD.
Figure 3 — Hierarchical topology of generic cabling
4.4 Cabling subsystems
4.4.1 Data centre cabling subsystems
4.4.1.1 Zone distribution cabling subsystem
The zone distribution cabling subsystem extends from a ZD to the EOs connected to it. The subsystem
includes:
a) the zone distribution cables;
b) the mechanical termination of the zone distribution cables at the EO and the ZD together with associated
patch cords and/or jumpers at the ZD;
c) LDPs (optional);
d) LDP cables (optional);
e) the EOs.
Although equipment cords are used to connect the transmission equipment to the cabling subsystem, they
are not considered part of the cabling subsystem because they can be application-specific.
Zone distribution cables shall be continuous from the ZD to the EOs unless an LDP is installed (see 4.8.5.2).
4.4.1.2 Intermediate distribution cabling subsystem
The intermediate distribution cabling subsystem extends from an ID to the ZDs connected to it. The
subsystem includes:
a) the intermediate distribution cables;
b) the mechanical termination of the intermediate distribution cables at the ID together with associated
patch cords and/or jumpers at the ID;
c) the mechanical termination of the intermediate cables at the ZD.
Although equipment cords are used to connect the transmission equipment to the cabling subsystem, they
are not considered part of the intermediate distribution cabling subsystem because they can be application-
specific.
4.4.1.3 Main distribution cabling subsystem
The main distribution cabling subsystem extends from an MD to the IDs connected to it. The subsystem
includes:
a) the main distribution cables;
b) the mechanical termination of the main distribution cables at the MD together with associated patch
cords and/or jumpers at the MD;
c) the mechanical termination of the main distribution cables at the ID.
Although equipment cords are used to connect the transmission equipment to the cabling subsystem, they
are not considered part of the main distribution cabling subsystem because they can be application-specific.
4.4.1.4 Network access cabling subsystem
The network access cabling subsystem extends from an MD, ID or ZD to the ENIs and/or other distributors of
the EN 50173 series connected to it. The subsystem includes:
a) the network access cables;
b) the mechanical termination of the network access cables at the ENI;
c) the mechanical termination of the network access cables at the MD, ID, ZD or other distributors of the
EN 50173 series.
Although equipment cords are used to connect the transmission equipment to the cabling subsystem, they
are not considered part of the network access cabling subsystem because they can be application-specific.
4.4.2 Associated cabling subsystems
4.4.2.1 Building backbone cabling
See EN 50173-1.
4.4.2.2 Campus backbone cabling
See EN 50173-1.
4.4.2.3 Other
Data centres within industrial premises can also be associated with floor cabling subsystems of EN 50173-3
for floor cabling subsystem.
4.5 Design objectives
4.5.1 General
The design objectives should address the performance and capacity aspects described in 4.5.2 to 4.5.5.
In addition, the design should support objectives of reliability (by means of design choices addressing
resilience, redundancy and disaster recovery) and any requirements for localized security. Measures that can
be considered (see Figure 4) include:
a) multiple and physically separated building entrances (as described in EN 50600-2-4);
b) redundant and physically separated ENIs with service provisioned in the ENIs in facilities served by
multiple service providers;
c) multiple and physically separated distributors;
d) diversely routed cabling between distributors;
e) tie cabling providing connection between distributors at the same hierarchical level as described in 4.5.6.
4.5.2 Zone distribution cabling
The zone distribution cabling should be designed to support the broadest set of existing and emerging
applications within the environmental conditions defined in Clause 5 and therefore provide the longest
operational life. This will minimize disruption and the high cost of re-cabling in the computer room space.
4.5.3 Intermediate distribution cabling
It is generally not possible or economically viable to install intermediate distribution cabling for the entire life of
the generic cabling system. Instead, the design should be based on current and foreseeable application
requirements. Such short-term selection criteria are particularly appropriate where there is good physical
access to pathways for future changes.
4.5.4 Main distribution cabling
It is generally not possible or economically viable to install main distribution cabling for the entire life of the
generic cabling system. Instead, the design should be based on current and foreseeable application
requirements. Such short-term selection criteria are particularly appropriate where there is good physical
access to pathways for future changes.
4.5.5 Network access cabling
The selection of network access cabling can require a longer term approach than that adopted for the main
distribution and intermediate distribution cabling if access to pathways is more limited.
Figure 4 — Examples
...

SLOVENSKI STANDARD
01-oktober-2018
Nadomešča:
SIST EN 50173-5:2008
SIST EN 50173-5:2008/A1:2011
SIST EN 50173-5:2008/A1:2011/AC:2011
SIST EN 50173-5:2008/A2:2013
Informacijska tehnologija - Generični kabelski sistemi - 5. del: Podatkovna
središča
Information technology - Generic cabling systems - Part 5: Data centre spaces
Informationstechnik - Anwendungsneutrale Kommunikationskabelanlagen - Teil 5:
Rechenzentrumsbereiche
Technologies de l'information - Systèmes de câblage générique - Partie 5: Espaces de
centres de traitement de données
Ta slovenski standard je istoveten z: EN 50173-5:2018
ICS:
33.040.50 Vodi, zveze in tokokrogi Lines, connections and
circuits
35.110 Omreževanje Networking
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD EN 50173-5
NORME EUROPÉENNE
EUROPÄISCHE NORM
June 2018
ICS 33.040.50 Supersedes EN 50173-5:2007
English Version
Information technology - Generic cabling systems - Part 5: Data
centre spaces
Technologies de l'information - Systèmes de câblage Informationstechnik - Anwendungsneutrale
générique - Partie 5: Espaces de centres de traitement de Kommunikationskabelanlagen - Teil 5:
données Rechenzentrumsbereiche
This European Standard was approved by CENELEC on 2018-03-19. CENELEC members are bound to comply with the CEN/CENELEC
Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.
Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC
Management Centre or to any CENELEC member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CENELEC member into its own language and notified to the CEN-CENELEC Management Centre has the
same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic,
Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden,
Switzerland, Turkey and the United Kingdom.

European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2018 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN 50173-5:2018 E
Contents Page
European foreword . 5
Introduction . 6
1 Scope and conformance . 9
1.1 Scope . 9
1.2 Conformance . 9
2 Normative references . 10
3 Terms, definitions and abbreviations . 10
3.1 Terms and definitions . 10
3.2 Abbreviations . 12
4 Structure of the generic cabling system in computer room spaces of data centres . 12
4.1 General. 12
4.2 Functional elements . 12
4.3 Structure and hierarchy . 13
4.4 Cabling subsystems . 14
4.4.1 Data centre cabling subsystems . 14
4.4.2 Associated cabling subsystems . 15
4.5 Design objectives . 16
4.5.1 General. 16
4.5.2 Zone distribution cabling . 16
4.5.3 Intermediate distribution cabling . 16
4.5.4 Main distribution cabling . 16
4.5.5 Network access cabling . 16
4.5.6 Tie cabling . 17
4.6 Accommodation of functional elements . 18
4.6.1 General. 18
4.6.2 Equipment Outlets . 18
4.6.3 Distributors . 18
4.6.4 Cables . 18
4.6.5 Local Distribution Points . 18
4.6.6 External Network Interface . 18
4.7 Interfaces . 18
4.7.1 Equipment interfaces and test interfaces . 18
4.7.2 Channels and links . 20
4.8 Dimensioning and configuration . 20
4.8.1 Distributors . 20
4.8.2 Cables . 20
4.8.3 Connecting hardware . 20
4.8.4 Cords. 20
4.8.5 Equipment Outlets and Local Distribution Points . 21
4.8.6 External Network Interface . 21
5 Channel performance in computer room spaces of data centres . 22
5.1 General. 22
5.2 Environmental performance . 23
5.3 Transmission performance. 23
5.3.1 General. 23
5.3.2 Balanced cabling . 23
5.3.3 Optical fibre cabling . 24
6 Reference implementations in computer room spaces of data centres . 24
6.1 General. 24
6.2 Balanced cabling . 24
6.2.1 General. 24
6.2.2 Zone distribution cabling . 24
6.2.3 Intermediate distribution cabling . 29
6.2.4 Main distribution cabling . 30
6.2.5 Network access cabling . 32
6.3 Optical fibre cabling . 34
6.3.1 General. 34
6.3.2 Component choice . 35
6.3.3 Dimensions . 35
7 Cable requirements in computer room spaces of data centres . 35
7.1 General. 35
7.2 Balanced cables of Category 5, 6, 6A, 7, 7A, 8.1 and 8.2. 35
7.3 Optical fibre cables of Category OM3, OM4, OM5, OS1a and OS2 . 35
8 Connecting hardware requirements in computer room spaces of data centres . 35
8.1 General requirements . 35
8.2 Balanced connecting hardware . 36
8.2.1 General requirements . 36
8.2.2 Electrical, mechanical and environmental performance . 36
8.3 Optical fibre connecting hardware . 36
8.3.1 General requirements . 36
8.3.2 Optical, mechanical and environmental performance . 37
9 Requirements for cords and jumpers in computer room spaces of data centres . 37
9.1 Jumpers . 37
9.2 Balanced cords of Category 5, 6, 6A, 7, 7A, 8.1 and 8.2 . 37
9.2.1 General. 37
9.2.2 Additional requirements for certain cords . 37
9.3 Optical fibre cords of Category OM3, OM4, OM5, OS1a and OS2 . 37
Annex A (normative) Link performance limits. 38
A.1 General. 38
A.2 Balanced cabling . 39
A.3 Optical fibre cabling . 39
Annex B (normative) Usage of high density connecting hardware within optical fibre cabling . 40
B.1 General. 40
B.2 Examples of cabling configurations using high density connecting hardware . 40
B.3 Channel performance . 40
Annex C (normative) Combination of balanced cabling links . 43
C.1 General. 43
C.2 Requirements . 43
Bibliography . 44
Figures
Figure 1 — Schematic relationship between the EN 50173 series and other relevant standards . 7
Figure 2 — Structure of generic cabling . 13
Figure 3 — Hierarchical topology of generic cabling . 14
Figure 4 — Examples of cabling implementation to improve reliability . 17
Figure 5 — Example of accommodation of functional elements. 18
Figure 6 — Test and equipment interfaces . 19
Figure 7 — The External Network Interface . 21
Figure 8 — Example of a channel . 22
Figure 9 — Example of a system showing the location of cabling interfaces . 23
Figure 10 — Zone distribution cabling models . 27
Figure 11 — Intermediate distribution cabling model . 29
Figure 12 — Main distribution cabling model. 31
Figure 13 — Network access cabling model . 33
Figure A.1 — Link options . 38
Figure B.1 — Examples of high density connecting hardware within main distribution cabling . 41
Figure B.2 — Examples of high density connecting hardware at the LDP and EO within zone
distribution cabling . 42
Figure C.1 — Examples of combination of different links . 43
Tables
Table 1 — Contextual relationship between EN 50173 series and other standards relevant for
information technology cabling systems . 7
Table 2 — Zone distribution channel equations . 28
Table 3 — Intermediate distribution channel equations . 30
Table 4 — Main distribution channel equations . 32
Table 5 — Network access cabling channel equations . 34
European foreword
This document (EN 50173-5:2018) has been prepared by the Technical Committee CENELEC TC 215
"Electrotechnical aspects of telecommunication equipment".
The following dates are fixed:
• latest date by which this document has (dop) 2019-03-19
to be implemented at national level by
publication of an identical national
standard or by endorsement
• latest date by which the national (dow) 2021-03-19
standards conflicting with this document
have to be withdrawn
This document supersedes EN 50173-5:2007 + A1:2010 + AC:2011 + A2:2012.
The European Standards EN 50173:1995 and EN 50173-1:2002 have been developed to enable the
application-independent cabling to support ICT applications in office premises. Their basic principles,
however, are applicable to other types of applications and in other types of premises.
TC 215 has decided to establish relevant European Standards which address the specific requirements of
these premises. In order to point out the commonalities of these cabling design standards, these EN are
published as individual parts of the series EN 50173, thus also acknowledging that standards users recognize
the designation “EN 50173” as a synonym for generic cabling design.
At the time of publication of this European Standard, series EN 50173 comprises the following standards:
EN 50173-1 Information technology — Generic cabling systems — Part 1: General requirements
EN 50173-2 Information technology — Generic cabling systems — Part 2: Office spaces
EN 50173-3 Information technology — Generic cabling systems — Part 3: Industrial spaces
EN 50173-4 Information technology — Generic cabling systems — Part 4: Homes
EN 50173-5 Information technology — Generic cabling systems — Part 5: Data centre spaces
EN 50173-6 Information technology — Generic cabling systems — Part 6: Distributed building
services
This edition of EN 50173-5:
a) introduces new components 8.1 and 8.2 for balanced cabling to support new channel Classes I and II as
well as optical fibre cabling (OM5) as defined in EN 50173-1:2018;
b) clarifies that the cabling defined in this standard applies to computer rooms in data centres;
c) aligns the document structure across the EN 50173 series and updates the document both technically
and editorially.
Introduction
The importance of cabling infrastructure is similar to that of other fundamental utilities such as water and
energy supply and interruptions to the services provided over that infrastructure can have a serious impact. A
lack of design foresight, the use of inappropriate components, incorrect installation, poor administration or
inadequate support can threaten quality of service and have commercial consequences for all types of users.
This standard specifies generic cabling within computer room spaces in data centre premises, or data centre
spaces within other types of building.
Additionally those premises can include:
— office spaces for which generic cabling is specified in EN 50173-2;
— industrial spaces for which generic cabling is specified in EN 50173-3.
Generic cabling for distributed building services in data centre spaces is specified in EN 50173-6 which
addresses all of the above premises and spaces within them.
Figure 1 and Table 1 show the schematic and contextual relationships between the standards produced by
TC 215 for information technology cabling, namely:
1) this and other parts of the EN 50173 series;
2) installation (EN 50174 series);
3) bonding (EN 50310).
Figure 1 — Schematic relationship between the EN 50173 series and other relevant standards
Table 1 — Contextual relationship between EN 50173 series and other standards relevant for
information technology cabling systems
Building design Generic cabling Specification Installation Operation phase
phase design phase phase phase
EN 50173-2 EN 50174-1
EN 50173-3
Planning phase
EN 50173-4
EN 50174-2
EN 50173-5
EN 50310 EN 50174-3 EN 50174-1
EN 50173-6
EN 50174-2
EN 50310
EN 50174-3
(these ENs
EN 50310
reference general
requirements of
EN 50173-1)
In addition, a number of Technical Reports have been developed to support or extend the application of these
standards, including:
— CLC/TR 50173-99-1, Cabling guidelines in support of 10 GBASE-T;
— CLC/TR 50173-99-2, Information technology — Implementation of BCT applications using cabling in
accordance with EN 50173-4;
— CLC/TR 50173-99-3, Information technology — Generic cabling systems — Part 99-3: Home cabling
infrastructures up to 50 m in length to support simultaneous and non simultaneous provision of
applications.
In addition, a number of cabling design standards have been developed using components of EN 50173-1
(e.g. EN 50098 series and EN 50700).
The generic cabling specified by this standard provides users with:
— an application independent system capable of supporting a wide range of applications in a range of
installation and operating environments;
— a flexible scheme such that modifications are both easy and economical;
— a multi-vendor supply chain within an open market for cabling components.
In addition this standard provides:
a) relevant industry professionals with guidance allowing the accommodation of cabling before specific
requirements are known; i.e. in the initial planning either for construction or refurbishment and for further
deployment as the requirements of areas are defined;
b) industry and standardization bodies with a cabling system which supports current products and provides
a basis for future product development and applications standardization.
Applications addressed in this standard include those developed by the Technical Committees of IEC
(including the subcommittees of ISO/IEC JTC 1) and study groups of ITU-T within the densely connected
environment of data centre spaces.
Physical layer requirements for the applications listed in EN 50173-1:2018, Annex F, have been analysed to
determine their compatibility with the cabling performance specified in this standard and, together with
statistics concerning premises geography from different countries and the models described in Clause 4,
have been used to develop the requirements for cabling components and to stipulate their arrangement into
cabling systems.
As a result, this standard:
a) specifies a structure for generic cabling supporting a wide variety of applications including, but not
restricted to, those in EN 50173-1:2018, Annex F;
b) adopts balanced cabling channel and link Classes EA, F, FA, I and II specified in EN 50173-1;
c) adopts optical fibre cabling channel and link requirements specified in EN 50173-1;
d) adopts component requirements, specified in EN 50173-1, and specifies cabling implementations that
ensures performance of links and of channels meeting the requirements of a specified group (e.g. Class)
of applications.
Life expectancy of generic cabling systems can vary depending on environmental conditions, supported
applications, aging of materials used in cables, and other factors such as access to pathways (campus
pathways are more difficult to access than building pathways).
With appropriate choice of components, generic cabling systems meeting the requirements of this standard
are expected to have a life expectancy of at least ten years.
This document should be read in conjunction with EN 50600-2-4 which describes other aspects of
telecommunications cabling in the computer room and other spaces of data centres.
1 Scope and conformance
1.1 Scope
This standard specifies generic cabling within computer room spaces in data centre premises, or data centre
spaces within other types of building.
It covers balanced cabling and optical fibre cabling.
This standard specifies directly or via reference to EN 50173-1 the:
— structure and minimum configuration for generic cabling within data centre spaces;
— interfaces at the external network interface (ENI) and equipment outlet (EO);
— performance requirements for cabling links and channels;
— implementation requirements and options;
— performance requirements for cabling components;
— conformance requirements and verification procedures.
This standard has taken into account requirements specified in application standards listed in EN 50173-1.
Safety and electromagnetic compatibility (EMC) requirements are outside the scope of this standard and are
covered by other standards and regulations. However, information given in this standard can be of assistance
in meeting these standards and regulations.
1.2 Conformance
For a cabling installation to conform to this standard the following applies.
a) The configuration and structure shall conform to the requirements of Clause 4.
b) Channels shall meet the requirements of Clause 5.
This shall be achieved by one of the following:
1) a channel design and implementation ensuring that the prescribed channel performance of Clause 5
is met;
2) attachment of appropriate components to a permanent link or LDP link design meeting the
prescribed performance class of Annex A. Channel performance shall be ensured where a channel
is created by adding more than one cord to either end of a link meeting the requirements of
Annex A;
3) for E environments, using the reference implementations of Clause 6 and compatible cabling
components conforming to the requirements of Clauses 7, 8 and 9 based upon a statistical
approach of performance modelling.
c) The interfaces to the cabling at the EO and ENI shall conform to the requirements of Clause 8 with
respect to mating interfaces and performance.
d) Connecting hardware at other places in the cabling structure shall meet the performance requirements
specified in Clause 8 independent of the interface used.
e) The requirements of EN 50174 series standards and EN 50310 shall be met.
f) Local regulations, including those concerning safety and EMC, shall be met.
This standard does not specify which tests and sampling levels should be adopted. Test methods to assess
conformance with the channel and link requirements of Clause 5 and Annex A respectively are specified in
EN 50173-1. The test parameters to be measured, the sampling levels and the treatment of measured results
to be applied for a particular installation shall be defined in the installation specification and quality plans for
that installation prepared in accordance with EN 50174-1.
In the absence of the channel, the conformance of the link shall be used to verify conformance with the
standard.
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.
EN 50173-1:2018, Information technology — Generic cabling systems — Part 1: General requirements
EN 50174-1, Information technology — Cabling installation — Part 1: Installation specification and quality
assurance
EN 50174-2, Information technology — Cabling installation — Part 2: Installation planning and practices
inside buildings
EN 50174-3, Information technology — Cabling installation — Part 3: Installation planning and practices
outside buildings
EN 61076-3-106:2006, Connectors for electronic equipment — Product requirements — Part 3-106:
Rectangular connectors — Detail specification for protective housings for use with 8-way shielded and
unshielded connectors for industrial environments incorporating the IEC 60603-7 series interface (IEC 61076-
3-106:2006)
EN 61076-3-110, Connectors for electronic equipment — Product requirements — Part 3-110: Detail
specification for shielded, free and fixed connectors for data transmission with frequencies up to 1 000 MHz
(IEC 61076-3-110)
EN 61754-7-1, Fibre optic interconnecting devices and passive components — Fibre optic connector
interfaces — Part 7-1: Type MPO connector family — One fibre row (IEC 61754-7-1)
EN IEC 61754-7-2, Fibre optic interconnecting devices and passive components — Fibre optic connector
interfaces — Part 7-2: Type MPO connector family — Two fibre rows (IEC 61754-7-2)
EN 61754-20:2012, Fibre optic interconnecting devices and passive components — Fibre optic connector
interfaces — Part 20: Type LC connector family (IEC 61754 20:2012)
3 Terms, definitions and abbreviations
3.1 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 50173-1 and EN 50174-1 and the
following apply.
3.1.1
computer room space
area within the data centre that accommodates the data processing, data storage and telecommunication
equipment that provides the primary function of the data centre
3.1.2
data centre
structure, or group of structures, dedicated to the centralized accommodation, interconnection and operation
of information technology and network telecommunications equipment providing data storage, processing and
transport services together with all the facilities and infrastructures for power distribution and environmental
control together with the necessary levels of resilience and security required to provide the desired service
availability
Note 1 to entry: A structure can consist of multiple buildings and/or spaces with specific functions to support the primary
function.
Note 2 to entry: The boundaries of the structure or space considered the data centre which includes the information and
communication technology equipment and supporting environmental controls can be defined within a larger structure or
building.
[SOURCE: EN 50600-1:2012, 3.1.9, modified – added Note 2 to entry]
3.1.3
equipment outlet
fixed connecting device where the zone distribution cabling terminates and providing the interface to the
equipment cabling
3.1.4
intermediate distribution cable
cable connecting the intermediate distributor to the zone distributor
3.1.5
intermediate distributor
distributor used to make connections between the main distribution cabling subsystem, intermediate
distribution cabling subsystem, network access cabling subsystem and active equipment
3.1.6
local distribution point
connection point in the zone distribution cabling subsystem between a zone distributor and one or more
equipment outlets
3.1.7
local distribution point cable
LDP cable
cable connecting a local distribution point to an equipment outlet
3.1.8
local distribution point link
LDP link
transmission path between a local distribution point and the interface at the other end of the zone distribution
cable including the connecting hardware at each end
3.1.9
main distribution cable
cable connecting the main distributor to the intermediate distributor
3.1.10
main distributor
distributor used to make connections between the main distribution cabling subsystem, network access
cabling subsystem and active equipment
3.1.11
network access cable
cable connecting the external network interface (or other distributors of the EN 50173 series) to the main
distributor, intermediate distributor or zone distributor
3.1.12
zone distribution cable
cable connecting the zone distributor to the equipment outlet(s) or local distribution point(s)
3.1.13
zone distributor
distributor used to make connections between the main distribution cabling subsystem, zone distribution
cabling subsystem, network access cabling subsystem and active equipment
3.2 Abbreviations
For the purposes of this document, the abbreviations of EN 50173-1 and the following apply.
BEF Building entrance facility
ENI External network interface
EO Equipment outlet
ID Intermediate distributor
LDP Local distribution point
MD Main distributor
OE EQP Opto-electronic equipment
ZD Zone distributor
4 Structure of the generic cabling system in computer room spaces of data centres
4.1 General
This clause identifies the functional elements of generic cabling, describes how they are connected together
to form subsystems and identifies the interfaces at which application-specific components are connected to
the generic cabling infrastructure. Channels, created by connecting application-specific cabling components
to the generic cabling, are used to support applications. Applications listed in EN 50173-1:2018, Annex F, are
supported by connecting active equipment at the external network interfaces, equipment outlets and the
distributors.
4.2 Functional elements
This standard specifies the following functional elements and interfaces of generic cabling:
a) external network interface (ENI);
b) network access cable;
c) main distributor (MD);
d) main distribution cable;
e) intermediate distributor (ID) ;
f) intermediate distribution cable;
g) zone distributor (ZD);
h) zone distribution cable;
i) local distribution point (LDP);
j) local distribution point cable (LDP cable);
k) equipment outlet (EO).
Groups of these functional elements are connected together to form cabling subsystems (see 4.3).
4.3 Structure and hierarchy
Generic cabling systems contain up to four types of cabling subsystems: network access, main distribution,
intermediate distribution and zone distribution. Where present and required, distributors of other parts of the
EN 50173 series within the premises can be connected to the generic cabling using the network access
cabling.
The cabling subsystems are connected together to create a generic cabling system with a structure as shown
in Figure 2. The composition of the cabling subsystems is described in 4.4.1. The functional elements of the
cabling subsystems are interconnected to form a basic hierarchical topology as shown in Figure 3.
Where the functions of distributors are combined (see 4.8.1) the cabling subsystems linking them are not
required.
Connections between cabling subsystems are either active, requiring application-specific equipment, or
passive. Connection to application-specific equipment at an MD and ZD adopts an interconnect or a cross-
connect approach (see EN 50173-1). Connection to application-specific equipment at an ENI and EO adopts
an interconnect approach (see EN 50173-1). Passive connections between cabling subsystems adopt either
a cross-connect approach, by way of either patch cords or jumpers, or an interconnect approach.

NOTE The ENI and/or distributors in accordance with EN 50173-1 can also be connected via network access
cabling to an ID or ZD.
Figure 2 — Structure of generic cabling
NOTE Network access cabling is also used to connect distributors of the EN 50173 series, and ENIs, to the ID and/or
ZD.
Figure 3 — Hierarchical topology of generic cabling
4.4 Cabling subsystems
4.4.1 Data centre cabling subsystems
4.4.1.1 Zone distribution cabling subsystem
The zone distribution cabling subsystem extends from a ZD to the EOs connected to it. The subsystem
includes:
a) the zone distribution cables;
b) the mechanical termination of the zone distribution cables at the EO and the ZD together with associated
patch cords and/or jumpers at the ZD;
c) LDPs (optional);
d) LDP cables (optional);
e) the EOs.
Although equipment cords are used to connect the transmission equipment to the cabling subsystem, they
are not considered part of the cabling subsystem because they can be application-specific.
Zone distribution cables shall be continuous from the ZD to the EOs unless an LDP is installed (see 4.8.5.2).
4.4.1.2 Intermediate distribution cabling subsystem
The intermediate distribution cabling subsystem extends from an ID to the ZDs connected to it. The
subsystem includes:
a) the intermediate distribution cables;
b) the mechanical termination of the intermediate distribution cables at the ID together with associated
patch cords and/or jumpers at the ID;
c) the mechanical termination of the intermediate cables at the ZD.
Although equipment cords are used to connect the transmission equipment to the cabling subsystem, they
are not considered part of the intermediate distribution cabling subsystem because they can be application-
specific.
4.4.1.3 Main distribution cabling subsystem
The main distribution cabling subsystem extends from an MD to the IDs connected to it. The subsystem
includes:
a) the main distribution cables;
b) the mechanical termination of the main distribution cables at the MD together with associated patch
cords and/or jumpers at the MD;
c) the mechanical termination of the main distribution cables at the ID.
Although equipment cords are used to connect the transmission equipment to the cabling subsystem, they
are not considered part of the main distribution cabling subsystem because they can be application-specific.
4.4.1.4 Network access cabling subsystem
The network access cabling subsystem extends from an MD, ID or ZD to the ENIs and/or other distributors of
the EN 50173 series connected to it. The subsystem includes:
a) the network access cables;
b) the mechanical termination of the network access cables at the ENI;
c) the mechanical termination of the network access cables at the MD, ID, ZD or other distributors of the
EN 50173 series.
Although equipment cords are used to connect the transmission equipment to the cabling subsystem, they
are not considered part of the network access cabling subsystem because they can be application-specific.
4.4.2 Associated cabling subsystems
4.4.2.1 Building backbone cabling
See EN 50173-1.
4.4.2.2 Campus backbone cabling
See EN 50173-1.
4.4.2.3 Other
Data centres within industrial premises can also be associated with floor cabling subsystems of EN 50173-3
for floor cabling subsystem.
4.5 Design objectives
4.5.1 General
The design objectives should address the performance and capacity aspects described in 4.5.2 to 4.5.5.
In addition, the design should support objectives of reliability (by means of design choices addressing
resilience, redundancy and disaster recovery) and any requirements for localized security. Measures that can
be considered (see Figure 4) include:
a) multiple and physically separated building entrances (as described in EN 50600-2-4);
b) redundant and physically separated ENIs with service provisioned in the ENIs in facilities served by
multiple service providers;
c) multiple and physically separated distributors;
d) diversely routed cabling between distributors;
e) tie cabling providing connection between distributors at the same hierarchical level as described in 4.5.6.
4.5.2 Zone distribution cabling
The zone distribution cabling should be designed to support the broadest set of existing and emerging
applications within the environmental conditions defined in Clause 5 and therefore provide the longest
operational life. This will minimize disruption and the high cost of re-cabling in the computer room space.
4.5.3 Intermediate distribution cabling
It is generally not possible or economically viable to install intermediate distribution cabling for the entire life of
the generic cabling system. Instead, the design should be based on current and foreseeable application
requirements. Such short-term selection criteria are particularly appropriate where there is good physical
access to pathways for future changes.
4.5.4 Main distribution cabling
It is generally not possible or economically viable to install main distribution cabling for the entire life of the
generic cabling system. Instead, the design should be based on current and foreseeable application
requirements. Such short-term selection criteria are particularly appropriate where there is good physical
access to pathways for future changes.
4.5.5 Network access cabling
The selection of network access cabling can require a longer term approach than that adopted for the main
distribution and intermediate distribution cabling if access to pathways is more limited.
Figure 4 — Examples of cabling implementation to improve reliabi
...