ISO/IEC 14709-1:1997
(Main)Information technology — Configuration of Customer Premises Cabling (CPC) for applications — Part 1: Integrated Services Digital Network (ISDN) basic access
Information technology — Configuration of Customer Premises Cabling (CPC) for applications — Part 1: Integrated Services Digital Network (ISDN) basic access
Technologies de l'information — Configuration du câblage dans les locaux d'usagers (CPC) pour les applications — Partie 1: Accès de base au réseau numérique à intégration de services (RNIS)
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Standards Content (Sample)
INTERNATIONAL ISOAEC
STANDARD 147094
First edition
1997-09-01
Information technology - Configuration of
Customer Premises Cabling (CPC) for
applications -
Part 1:
Integrated Services Digital Network (ISDN)
basic access
Technologies de I’informa tion - Configuration du &b/age dans /es locaux
d’usagers (CPC) pour /es applications -
Partie 1: AC&S de base au rkseau numkique & intbgration de services
(RN/S)
Reference number
lSO/IEC 14709-1:1997(E)
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lSO/IEC 14709-l :1997(E)
Contents
Foreword
iv
Introduction
1 Scope
1
2 Normative references
1
3 Definitions
4 Abbreviations and symbols
4.1 Abbreviations
4.2 Symbols
5 Design requirements
5.1 General
5.2 Insertion loss
5.3 Longitudinal conversion loss
5.4 Round trip delay
5.5 Power feeding
5.6 Electromagnetic environment
5.7 Spurs
5.8 Near-end crosstalk loss (NEXT)
6 Configurations
6.1 General
6.2 The point-to-point configuration
6.3 The short passive bus configuration
6.4 The extended passive bus configuration
6.5 The Y-configuration
6.6 The star configuration
6.7 Implementation over structured cabling systems
7 Minimum requirements for cabling components
7.1 General
7.2 Cables
7.3 Terminal cords
7.4 Terminating resistors
7.5 Outlets and joint boxes
7.6 Cross-connect products/patch cords
12
8 Cabling qualification
12
8.1 General
13
8.2 Spurs
13
8.3 Cabling integrity
13
8.4 D.c. loop resistance
13
8.5 D.c. lead resistance unbalance
13
8.6 Insulation resistance
13
8.7 Insertion loss
14
8.8 Round trip delay
14
8.9 Characteristic impedance
14
8.10 Near end crosstalk (NEXT) loss
14
8.11 Impulsive noise
14
8.12 Bit error rates
14
8.13 Longitudinal conversion loss
15
Annex A (informative) Bibliography
16
Annex B (informative) Examples of maximum distances for specific common cables
0 ISO/IEC 1997
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Printed in Switzerland
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Foreword
IS0 (the International Organization for Standardization) and IEC (the International Electrotechnical Commission)
form the specialized system for worldwide standardization. National bodies that are members of lS0 or lEC
participate in the development of International Standards through technical committees established by the
respective organization to deal with particular fields of technical activity. IS0 and IEC technical committees
collaborate in fields of mutual interest. Other international organizations, governmental and non-governmental, in
liaison with IS0 and IEC, also take part in the work.
In the field of information technology, IS0 and IEC have established a joint technical committee, ISOAEC JTC 1.
Draft International Standards adopted by the joint technical committee are circulated to national bodies for voting.
Publication as an International Standard requires approval by at least 75 % of the national bodies casting a vote.
International Standard lSO/IEC 14709-I was prepared by Joint Technical Committee lSO/IEC JTC 1, information
technology, Subcommittee SC 25, Interconnection of information technology equipment.
ISOAEC 14709 consists of the following parts, under the general title Information technology - Configuration of
Customer Premises Cabling (CPC) for applications:
- Part I: Integrated Services Digital Network (/SON) basic access
- Part 2: Integrated Services Digital Network (/SON) primary access
Annexes A and B of this part of lSO/IEC 14709 are for information only.
. . .
III
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lSO/IEC 14709-l : 1997(E)
Introduction
This part of lSO/IEC 14709 is intended for use by those designing, planning or procuring cabling for ISDN basic
access within a customer’s premises. The configurations in this part of ISOAEC 14709 are designed to be effective
when either implemented with cabling having the recommended characteristics, or implemented with the
components specified in clause 7. In addition, guidance is given for the use of generic cabling in accordance with
lSO/IEC 11801.
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ISO/IEC 14709=1:1997(E)
INTERNATIONAL STANDARD @ lSO/IEC
Information technology - Configuration of Customer Premises Cabling
(CPC) for applications -
Part 1:
Integrated Services Digital Network (ISDN) basic access
1 Scope
This part of ISO/IEC 14709 defines the requirements for the design and configuration of customer premises
cabling for the connection of basic access ISDN equipment.
It defines
design requirements for ISDN basic access with point-to-point and point-to-multipoint cabling configurations;
-
- minimum cabling requirements for the installation of new cabling;‘)
- criteria for the use of generic cabling;
- criteria for the use of existing cabling.
This part of ISO/IEC 14709 applies to the customer premises cabling. It describes the cabling requirements,
needed to transmit ISDN basic access signals as defined by ITU-T Recommendation 1.430. The requirements
placed on the customer premises cabling are solely those necessary to enable terminal equipment conforming to
ITU-T Rec. 1.430 to operate into the Network Termination (NT) via configurations defined in this part of ISO/IEC
14709.
2 Normative references
The following standards contain provisions which, through reference in this text, constitute provisions of this part o
ISO/IEC 14709. At the time of publication, the editions indicated were valid. All standards are subject to revision
and parties to agreements based on this part of lSO/IEC 14709 are encouraged to investigate the possibility o
applying the most recent editions of the standards indicated below. Members of IEC and IS0 maintain registers o
currently valid International Standards.
lSO/IEC 8877:1992, Information technology - Telecommunications and information exchange between
systems - Interface connector and contact assignments for ISDN Basic Access
Interface located at reference points S and T.
lnforma tion technology - Generic cabling for customer premises.
lSO/IEC 11801:1995,
I EC 603-7: 1996, Connectors for frequencies below 3 MHz for use with printed boards - Part 7: Detail
specification for connectors, g-way, including fixed and free connectors with common
mating features, with assessed quality.
ISDN user-network interface; Layer I recommendations.
ITU-T Ret 1.430
(Blue Book)
3 Definitions
The meaning of the term round trip delay can be found in ITU-T Recommendation 1.430 (Blue Book), A.2.
Furthermore, for the purposes of this part of lSO/IEC 14709, the following definitions apply.
3.1 cabling: The assembly of all cables, connections, patch panels and other passive components which comprise
the telecommunications infrastructure.
3.2 network termination: The functional group on the network side of a user-network interface.
NOTE: A network termination always comprises a transmission part NT1 and optionally a switching part NT2.
3.3 power feeding: The function which provides for the capability to transfer power across the interface of the NT.
3.4 terminal equipment: The functional group on the user side of a user-network interface.
NOTE: Terminal equipment includes terminal(s), terminal adapter(s) and, if any, NT2 functional group.
1) Although this part of lSO/IEC 14709 specifies the minimum requirements for cabling dedicated to OSDN basic
access, it is highly recommended that cabling newly installed complies with lSO/IEC 11801 class B or higher.
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4 Abbreviations and symbols
41 . Abbreviations
BD
Building distributor
CD Campus distributor
FD
Floor distributor
FFS For further study
ISDN Integrated services digital network
NEXT Near-end crosstalk loss
NT1 Network termination 1
NT2 Network termination 2
S S reference point
So interface
SO
SC Structured cabling
T T reference point
TE Terminal equipment
TP Transition Point
TR Terminating resistor
NOTE: The meanings of the abbreviations S, SO and T conform to ITU-T Recommendation 1.430.
42 . Symbols
cable
spur/tap with a junction to a cable which is the terminated bus
Network Termination
NT
c
Terminating Resistors
I3 outlet according to IEC 603-7
cl
a plug according to IEC 603-7
any socket
El
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any PUI
Joint at outlet
5 Design requirements
51 . General
Signals passing between the NT and TE(s) for the various configurations are subject to attenuation, delay and
distortion. Cabling components (including extension cords, adapters, cross-connect components, outlets, junction
boxes, cables, spurs etc.) and connected terminals all contribute to these effects. The design requirements for the
cabling are dependent on the configuration chosen.
52 . Insertion loss
The insertion loss is measured from the NT to the TR at 96 kHz with 100 s2 source and load impedances. The
maximum insertion loss for each configuration is shown in table 1.
Table 1 - Maximum insertion loss for each configuration
Configuration Insertion loss at 96 kHz
A
Point-to-point 6 dB
4 dB
Extended passive bus
Short passive bus not critical
Y-configuration not critical
53 . Longitudinal conversion loss
The longitudinal conversion loss of the cabling shall be equal to, or greater than, 43 dB when measured at 96 kHz.
54 . Round trip delay
The round trip delay introduced by the cabling shall not exceed:
a) 2,0 us for the total cabling of both the short passive bus at 96 kHz and the Y-configuration;
b) 0,5 us differential round trip delay for the cabling between the first and last outlet of the extended passive
bus.
These requirements are illustrated in figure 1.
55 . Power feeding
The length of the cabling may be limited by the cable resistivity, the number of terminals, their power consumption
and the capability of the remote power sources.
The loop resistance has to be controlled in order to fulfil the power feeding requirements and to avoid static
saturation of inductive components in NT and TEs due to the difference in d.c. resistances of the two wires making
up the twisted pair. The d.c. resistance unbalance of the two wires shall not exceed 3 % if the loop resistance is
greater than 5 0.
In the majority of cases power is supplied via the phantom of the transmit and receive pairs In this case only two
pairs are used. In some applications a third pair is needed for power source 2 and power sink 2.
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\ *
a 14
I3 ’ ’ r”l NT
cl
II
a
First outlet
Last outlet
A Q,O ps
For the short passive bus configuration:
For the extended Passive bus confiwration: A - B < 0,5 us
Figure 1 - Round trip delay requirements
56 . Electromagnetic environment
The ISDN basic access is designed to work in most environments. However, its performance may be degraded by
interference from external electromagnetic sources (such as motors) and interference from other transmission
systems sharing the same cable.
The impulsive noise generated by, for instance, analogue telephony or unbalanced data interfaces, can cause
interference with signals carried on the ISDN cabling.
Crosstalk can be limited by using pairs for ISDN basic rate in separate cables or in separate bundles of pairs in the
same cable. Before sharing of ISDN S-bus with other transmission systems in the same cable it shall be verified
that they do not interfere with each other.
In noisy environments or adjacent to sensitive equipment, shielded cabling may be advisable. Cables routed
outside of buildings may require protection devices. The attenuation and capacitance of protection devices shall be
taken into account.
Spurs
57 .
Because spurs will add capacitance to the cabling, they are not recommended. When needed, the length of spurs
used for connection of terminal outlets shall not exceed 1 m. The length of a spur used to attach a NT should not
exceed 05 m.
Near-end crosstalk loss (NEXT)
5.8
The near-end crosstalk loss of the cabling shall be greater than 35 dB at 96 kHz. It is recommended that the NEXT
of the cable be greater than 54 dB for satisfactory noise immunity (see 7.2).
6 Configurations
General
61 .
The following design requirements are common to all ISDN basic access user network interface configurations:
a) Where SO interfaces can be extended under fallback mode (e.g. when the NT2 is bypassed), further loss
and delay will be introduced into the link. The design requirements apply to worst case conditions.
b) The TE may be hardwired to the cable termination. If a TE cord is used it shall comply with ISO/IEC 8877.
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C) Terminating resistors (see 7.4) are needed at both ends of the transmit and receive pairs Locations are
If a specific configuration requires the terminating resistors at the
shown in figures 2 to 5 and figures 7 to 9.‘)
NT, these terminating resistors shall always be present either within the NT or at the connection point between
the NT (cord) and the bus cabling.
d) The NT may be connected to the cabling in three ways:
- hardwired;
with a outlet integral to the NT;
-
- via a flexible cord with a plug.
ISOAEC 8877 and IEC 603-7 may be applied for the case with a connector at the NT. If however hardwiring is
used, an outlet complying to ISOAEC 8877 and IEC 603-7 should be available close to the NT for supervision
and maintenance.
Configurations which can be supported within the hierarchical star topology allow the full flexibility of generic
cabling to be exploited. When planning configurations, the following should be taken into account:
1) point-to-point configurations including star (see 6.6) can easily be carried out via generic cabling defined in
ISOAEC 11801;
2) short passive bus can not be carried out via generic cabling defined in ISOAEC 11801. Extended passive
bus and Y-configurations can be carried out via generic cabling using adapters in the work area. See 6.7 for
implementation over structured cabling systems. Only two B-channels are available for all the possible
extension outlets of one single bus. Thus point-to-multipoint configurations can not replace PBX
functionality.
62 . The point-to-point configuration
The point-to-point configuration is illustrated in figure 2.
I
n II
-------m--m
NT
* r D
)
cl, II
/
TE
dl Total length of cabling from NT to outlet
*) TE connecting cord or integral cord
**) Optional extension cord
Maximum number of outlets: 1
Maximum number of terminals: 1
Figure 2 - Point-to-point configuration
Requirements
For a point-to-point configuration, the insertion loss at 96 kHz shall be less than 6 dB (see 5.2) over the distance
d-f in figure 2. This includes cabling and extension cords if used. Maximum distances can be found in annex B.
1) In generic cabling terminating resistors shall be placed external to the TO.
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The length of an optional extension cord shall not exceed 25 m.
It is recommended that the polarity of each wire be maintained throughout the length of the cabling to facilitate
testing and more effective cable management.
6.3 The short passive bus configuration
In the short passive bus configuration, outlets for the terminals are distributed at any point along the bus. A typical
short passive bus is illustrated in figure 3.
II
I
NT
d3
* *
*
) )
)
I
r
. ,
I
TE TE TE
d2 Total length of cabling from NT to last outlet
*) TE connecting cord or integral cord
Maximum number of outlets: 12
Maximum number of terminals: 8
Figure 3 - Short passive bus
Requirements
The round trip delay requirement for the short passive bus specified in 5.4a) applies to the bus length c/2 in
figure 3. Length a’2 is the total length of the cabling between the NT and the last outlet, it does not include the
length of spurs. Maximum distances can be found in annex B.
Not more than 8 terminals shall be connected to the short passive bus at any one time. The maximum number of
outlets connected directly to the bus is limited to 12, however, no more than 8 shall be attached via spurs.
NOTE: It may be necessary to plan for less than 8 terminals on a short passive bus to meet the anticipated traffic conditions.
It is recommended not to use spurs. However, if they are used they shall not exceed 1 m. A spur shall be
terminated with a single outlet.
The polarity of each wire of the twisted pair shall be maintained throughout the bus.
Extension cords shall not be used to extend the TE cord.
64 . The extended passive bus configuration
Up to 4 TEs are grouped together at the distant end of the bus to the NT,
A typical extended passive bus is illustrated in figure 4.
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d
n
u
I /
-
a
1
NT
I3
a
1
T
TE TE TE
d3 Length of cabling between first and last outlet
dq Length of cabling from NT to last outlet
*) TE connecting cord or integral cord
Maximum number of outlets: 12
Maximum number of terminals: 4
Figure 4 - Extended passive bus
Requirements
The insertion loss requirement for the extended passive bus specified in 5.2 applies to the length dq in figure 4.
The differential round trip delay requirement for the extended passive bus specified in 5.4b) applies to the length
63 in figure 4. Maximum distances can be found in annex B.
The number of terminals that may be connected to the bus shall not exceed 4.
NOTE: It may be necessary to plan for less than 4 terminals on an extended passive bus to meet the anticipated traffic conditions.
It is recommended not to use spurs. However, if spurs are present they shall not exceed 1 m.
The polarity of each wire of the twisted pairs shall be maintained throughout the bus.
Extension cords shall not be used to extend the TE cord.
65 . The Y-configuration
The Y-configuration is illustrated in figure 5.
NOTE: If the NT is equipped with terminating resistors, they may stay.
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