Business TeleCommunications (BTC); 2 048 kbit/s digital structured leased lines (D2048S); Attachment requirements for terminal equipment interface

Specification of the attachment requirements for a terminal equipment interface and test procedures for compliance.

Poslovne telekomunikacije (BTC) - Digitalni zakupljeni vodi za prenosno hitrost 2 048 kbit/s in za nestrukturirane signale (D2048U) - Priključitvene zahteve za vmesnik terminalske opreme

General Information

Status
Published
Publication Date
30-Sep-2004
Current Stage
6060 - National Implementation/Publication (Adopted Project)
Start Date
01-Oct-2004
Due Date
01-Oct-2004
Completion Date
01-Oct-2004
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SLOVENSKI STANDARD
SIST TBR 013 E1:2004
01-oktober-2004

3RVORYQHWHOHNRPXQLNDFLMH %7& 'LJLWDOQL]DNXSOMHQLYRGL]DSUHQRVQRKLWURVW

NELWVLQ]DQHVWUXNWXULUDQHVLJQDOH '8 3ULNOMXþLWYHQH]DKWHYH]D
YPHVQLNWHUPLQDOVNHRSUHPH
Business TeleCommunications (BTC); 2 048 kbit/s digital structured leased lines
(D2048S); Attachment requirements for terminal equipment interface
Ta slovenski standard je istoveten z: TBR 013 Edition 1
ICS:
33.040.50 Vodi, zveze in tokokrogi Lines, connections and
circuits
SIST TBR 013 E1:2004 en

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST TBR 013 E1:2004
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SIST TBR 013 E1:2004
TECHNICAL TBR 013
BASIS for January 1996
REGULATION
Source: ETSI TC-BTC Reference: DTBR/BTC-02037
ICS: 33.040.40
ONP, leased line, D2048S, terminal equipment
Key words:
Business TeleCommunications (BTC);
2 048 kbit/s digital structured leased lines (D2048S);
Attachment requirements for terminal equipment interface
ETSI
European Telecommunications Standards Institute
ETSI Secretariat
F-06921 Sophia Antipolis CEDEX - FRANCE
Postal address:
650 Route des Lucioles - Sophia Antipolis - Valbonne - FRANCE
Office address:
c=fr, a=atlas, p=etsi, s=secretariat - secretariat@etsi.fr
X.400: Internet:
Tel.: +33 92 94 42 00 - Fax: +33 93 65 47 16

Copyright Notification: No part may be reproduced except as authorized by written permission. The copyright and the

foregoing restriction extend to reproduction in all media.
© European Telecommunications Standards Institute 1996. All rights reserved.
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TBR 013: January 1996

Whilst every care has been taken in the preparation and publication of this document, errors in content,

typographical or otherwise, may occur. If you have comments concerning its accuracy, please write to

"ETSI Editing and Committee Support Dept." at the address shown on the title page.

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TBR 013: January 1996
Contents

Foreword .......................................................................................................................................................5

Introduction....................................................................................................................................................5

1 Scope ..................................................................................................................................................7

2 Normative references..........................................................................................................................7

3 Definitions and abbreviations ..............................................................................................................8

3.1 Definitions ............................................................................................................................8

3.2 Abbreviations.......................................................................................................................................8

4 Requirements......................................................................................................................................9

4.1 Physical characteristics........................................................................................................9

4.1.1 Hardwired connection....................................................................................10

4.1.2 Alternative means of connection ...................................................................10

4.2 Electrical characteristics ....................................................................................................10

4.2.1 Output port ....................................................................................................10

4.2.1.1 Signal coding .......................................................................10

4.2.1.2 Waveform shape .................................................................10

4.2.1.3 Output timing .......................................................................11

4.2.1.4 Output jitter ..........................................................................12

4.2.1.5 Output structure...................................................................13

4.2.1.5.1 CRC-4...................................................13
4.2.1.5.2 Use of the E-bits ...................................13
4.2.1.5.3 Use of the A-bit .....................................14
4.2.1.5.4 Use of the S bits .................................14

4.2.2 Input port .......................................................................................................14

4.3 Safety.................................................................................................................................14

4.4 Overvoltage protection.......................................................................................................14

4.4.1 Impulse transfer from mains, common mode ...............................................15

4.4.2 Impulse transfer from mains, transverse mode ............................................15

4.4.3 Conversion of common mode to transverse mode .......................................15

4.5 ElectroMagnetic Compatibility (EMC) ................................................................................15

Annex A (normative): Test methods......................................................................................................16

A.1 General..............................................................................................................................................16

A.1.1 Equipment connection .......................................................................................................16

A.1.2 Test environment ...............................................................................................................16

A.2 Test methods ....................................................................................................................................17

A.2.1 Signal coding at the output port .........................................................................................17

A.2.2 Waveform shape at output port .........................................................................................18

A.2.3 Clock accuracy at the output port ......................................................................................19

A.2.4 Output jitter ........................................................................................................................19

A.2.5 Frame structure .................................................................................................................21

Annex B (normative): Definition of HDB3 code .....................................................................................22

B.1 General..............................................................................................................................................22

B.2 Definition ...........................................................................................................................................22

Annex C (normative): Definition of frame structure ...............................................................................23

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TBR 013: January 1996

C.1 Frame structure ................................................................................................................................ 23

C.2 CRC-4............................................................................................................................................... 23

C.2.1 CRC-4 generation ............................................................................................................. 24

Annex D (normative): TBR Requirements Table (TBR-RT) ................................................................. 25

Annex E (informative): Bibliography ....................................................................................................... 26

History......................................................................................................................................................... 27

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TBR 013: January 1996
Foreword

This Technical Basis for Regulation (TBR) has been produced by the Business Telecommunications

(BTC) Technical Committee of the European Telecommunications Standards Institute (ETSI).

This TBR results from a mandate from the Commission of the European Community (CEC) to provide

harmonized standards for the support of the Second Phase Directive (91/263/EEC).

This TBR is based on information from ITU-T Recommendations and ETSI publications and the relevant

documents are quoted where appropriate.
Introduction

The Council Directive on the application of Open Network Provision (ONP) to leased lines (92/44/EEC)

concerns the harmonisation of conditions for open and efficient access to, and use of, the leased lines

provided on public telecommunications networks, and the availability throughout the European Union (EU)

of a minimum set of leased lines with harmonized technical characteristics.

The consequence of the Directive is that telecommunications organisations within the EU shall make

available a set of leased lines between points in these countries with specified connection characteristics

and specified interfaces.

Two classes of standard will be used for the interfaces of terminal equipment designed for connection to

the ONP leased lines. European Telecommunications Standards (ETSs), which are voluntary, give the full

technical specifications for these interfaces, whereas Technical Basis for Regulations (TBRs) give the

essential requirements under the Second Phase Directive (91/263/EEC) for attachment to the leased

lines. This TBR is a subset of the corresponding ETS 300 420.

CCITT Recommendations G.703, G.704 and G.706, as qualified by ETS 300 166, are used as the basis

for the terminal interface.
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1 Scope

This TBR specifies the attachment requirements and corresponding test principles for a terminal

equipment interface for connection to the Network Termination Points (NTPs) of ONP 2 048 kbit/s digital

structured leased lines (D2048S) using 120 õ interfaces with an information rate of 1 984 kbit/s without

restriction on binary content. A terminal equipment interface that conforms to this TBR will also conform

with TBR 012 for connection to an ONP 2 048 kbit/s unstructured leased line.

The term "attachment requirements" in the context of this TBR describes the essential requirements for

access which have to be fulfilled under the Second Phase Directive (91/263/EEC). Conformance to these

requirements does not guarantee end-to-end interoperability.

This TBR is applicable to all interfaces designed for connection to the ONP 2 048 kbit/s structured leased

line. It covers the essential requirements for the physical and electrical characteristics of the terminal

equipment interface.

Customer premises wiring and installation between the terminal equipment and the NTP are outside the

scope of this TBR.
2 Normative references

This TBR incorporates by dated and undated reference, provisions from other publications. These

normative references are cited at the appropriate places in the text and the publications are listed

hereafter. For dated references, subsequent amendments to or revisions of any of these publications

apply to this TBR only when incorporated into it by amendment or revision. For undated references the

latest edition of the publication referred to applies.
[1] CCITT Recommendation G.703 (1991): "Physical/electrical characteristics of
hierarchical digital interfaces".
[2] CCITT Recommendation G.704 (1991): "Synchronous frame structures used at
primary and secondary hierarchical levels".
[3] CCITT Recommendation O.151 (1992), subclause 2.1: "Error performance
measuring equipment for digital systems at the primary rate and above".
[4] CCITT Recommendation O.171 (1992): "Timing jitter measuring equipment for
digital systems".
[5] ETS 300 046-3 (1992): "Integrated Services Digital Network (ISDN); Primary
rate access - safety and protection, Part 3: Interface I - protection".

NOTE: This TBR also contains a number of informative references which have been included

to indicate the sources from which various material has been derived, hence they do

not have an associated normative reference number. Details of these publications are

given in annex E. In some cases the same publication may have been referenced in
both a normative and an informative manner.
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3 Definitions and abbreviations
3.1 Definitions
For the purposes of this TBR, the following definitions apply:

errored Sub-MultiFrame: A Sub-MultiFrame (SMF) where the calculated Cyclic Redundancy Check-4 bit

(CRC-4)1 does not correspond with the CRC-4 contained within the next SMF (see subclause C.2.2).

frame: A sequence of 256 bits of which the first 8 bits define the frame structure (see annex C).

leased lines: The telecommunications facilities provided by a public telecommunications network that

provide defined transmission characteristics between NTPs and that do not include switching functions

that the user can control, (e.g. on-demand switching).

multiframe: A sequence of two SMFs containing the multiframe alignment word (see annex C).

Network Termination Point (NTP): All physical connections and their technical access specifications

which form part of the public telecommunications network and are necessary for access to and efficient

communication through that public network.

PRBS(2 -1): Pseudo Random Bit Sequence (PRBS) (as defined in subclause 2.1 of CCITT

Recommendation O.151 [3]).

S bits: Bits 4 to 8 (bits S to S ) in frames not containing the frame alignment signal (see annex C).

a a4 a8

Safety Extra-Low Voltage (SELV) circuit: A secondary circuit which is so designed and protected that

under normal and single fault conditions, the voltage between any two accessible parts and, for class 1

equipment, between any accessible part and the equipment protective earthing terminal does not exceed

a safe value (subclause 1.2.8.5 of EN 60950).

Sub-Multiframe (SMF): A sequence of 8 frames, each of 256 bits, over which the CRC-4 is calculated

(see annex C).

terminal equipment: Equipment intended to be connected to the public telecommunications network, i.e.:

- to be connected directly to the termination of a public telecommunication network; or

- to interwork with a public telecommunications network being connected directly or indirectly to the

termination of a public telecommunications network,
in order to send, process, or receive information.
3.2 Abbreviations
For the purposes of this TBR, the following abbreviations apply:
ac alternating current
AIS Alarm Indication Signal
AMI Alternate Mark Inversion
CRC-4 Cyclic Redundancy Check-4 bit
D2048S 2 048 kbit/s digital structured leased line
dc direct current
EMC ElectroMagnetic Compatibility
HDB3 High Density Bipolar code of order 3 (see annex B)
NTP Network Termination Point
ONP Open Network Provision
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ppm parts per million
PRBS Pseudo Random Bit Sequence
RAI Remote Alarm Indication
RX RX is a signal input (at either the terminal equipment interface or the test
equipment, see figure 1)
SELV Safety Extra-Low Voltage
SMF Sub-MultiFrame
TX TX is a signal output (at either the terminal equipment interface or the test
equipment, see figure 1)
TBR-RT TBR Requirements Table
UI Unit Interval
4 Requirements

The terminal equipment interface is for use with 2 048 kbit/s structured leased lines which provide bi-

directional, point-to-point digital connections with an information transfer rate of 1 984 kbit/s without

restriction on binary content. Any structuring of the data within the transparent 1 984 kbit/s part of the

frame is the responsibility of the user.
4.1 Physical characteristics

Justification: Without a connection method defined, it is impossible for the terminal equipment to connect

to the network, therefore this is required for the terminal equipment to interwork with the network

(article 4f).

Currently no standardised connector is readily available. Consequently, the only method of connection that

can be specified in this TBR is the use of solid conductors of 0,4 mm to 0,6 mm. This TBR requires the

terminal equipment to be capable of presenting either a point for the attachment of unterminated solid

conductors, or solid conductors themselves (see subclause 4.1.1). It is a requirement that such a

connection method be available to be provided for use with the terminal equipment if necessary.

In order to allow connection to be made using other methods (e.g. connectors), the terminal equipment is

permitted to be supplied with a connection method suitable for use with those methods (see

subclause 4.1.2).

NOTE 1: The following are examples of arrangements that comply with the requirements. The

list below should not be regarded as an exhaustive list of all permitted arrangements:

a) a cord, permanently connected to the terminal equipment at one end and
unterminated at the other end, with wires that are solid conductors with
diameters in the range 0,4 mm to 0,6 mm;
b) a cord, connected via a plug and socket to the terminal equipment at one end
and unterminated at the other end, with wires that are solid conductors with
diameters in the range 0,4 mm to 0,6 mm;
c) an insulation displacement connector, designed to accept wires with solid
conductors with diameters in the range 0,4 mm to 0,6 mm, but with no cord;
d) a screw connector, designed to accept wires with solid conductors with
diameters in the range 0,4 mm to 0,6 mm, but with no cord;
e) the arrangement in b) plus one or more additional alternative cords with the
same plug or socket arrangement at the terminal end and any plug or socket at
the other end;
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f) the arrangement in c) or d) plus one or more cords suitable for connection to the

terminal equipment at one end and any plug or socket at the other end.

The transmit pair is the output from the terminal equipment interface. The receive pair is the input to the

terminal equipment interface, as shown in figure 1. Where the terms "output" and "input" are used without

qualification in this TBR, they refer to the terminal equipment interface.
˝˝˝˝˝˝˝˝˝˝˝˝»OUTPUTINPUT˝˝˝˝˝˝˝˝˝˝˝˝»
”TX˙˜˜˜˜˜˜˜˜˜˜˜˜˜>˜˜˜˜˜˜˜˜˜˜˜˜˜˜¶RX”
”NETWORK˙˜˜˜˜˜˜˜˜˜˜˜˜˜>˜˜˜˜˜˜˜˜˜˜˜˜˜˜¶TERMINAL”
”INTERFACE””EQUIPMENT”
”˙˜˜˜˜˜˜˜˜˜˜˜˜˜<˜˜˜˜˜˜˜˜˜˜˜˜˜˜¶”
”RX˙˜˜˜˜˜˜˜˜˜˜˜˜˜<˜˜˜˜˜˜˜˜˜˜˜˜˜˜¶TX”
¨˝˝˝˝˝˝˝˝˝˝˝˝…INPUTOUTPUT¨˝˝˝˝˝˝˝˝˝˝˝˝…
Figure 1

NOTE 2: The use of a shielded cord or cable may be necessary to meet radiation and immunity

requirements defined in ElectroMagnetic Compatibility (EMC) standards.
4.1.1 Hardwired connection
Requirement: The terminal equipment shall provide:

a) a set of connection contacts (e.g. an insulation displacement connector or a screw terminal block)

to which solid wire conductors with diameters in the range 0,4 mm to 0,6 mm may be connected; or

b) a wiring arrangement connected by any means to the terminal equipment, with unterminated solid

wire conductors with diameters in the range 0,4 mm to 0,6 mm at the end distant from the terminal

equipment.

Test: There is no test. All subsequent tests are carried out via the specified connection method.

4.1.2 Alternative means of connection

Any alternative means of connection may be provided in addition to the connection arrangements under

subclause 4.1.1.
4.2 Electrical characteristics
4.2.1 Output port
4.2.1.1 Signal coding

Justification: The correct signal coding is necessary for the output signals from the terminal equipment to

be received correctly at the input to the NTP, otherwise the leased line will not achieve frame alignment

and possibly send Alarm Indication Signal (AIS) forward within the network; therefore a requirement on

signal coding should be included for interworking with the network (article 4f).

Requirement: The signal transmitted at the output port shall comply with the High Density Bipolar code of

order 3 (HDB3) encoding rules (see annex B).
Test: The test shall be conducted according to subclause A.2.1.
4.2.1.2 Waveform shape

Justification: The correct waveform shape serves to limit the voltages to line preventing harm to the

network (article 4d). It is also necessary for the output signals from the terminal equipment to be received

correctly at the input to the NTP, otherwise the leased line will not achieve frame alignment and possibly

send AIS forward within the network; therefore a requirement on the waveform shape should be included

for interworking with the network (article 4f).
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Requirement: The pulse at the output port shall comply with the requirements given in table 1 and

figure 2; based on CCITT Recommendation G.703 [1].
Table 1: Waveform shape at output port
Pulse shape All marks of a valid signal must conform
(nominally rectangular) with the mask (see figure 2) irrespective
of the polarity. The value V corresponds
to the nominal peak voltage of a mark.
Test load impedance 120 õ non-reactive
Nominal peak voltage V of a mark 3 V
Peak voltage of a space 0 ± 0,3 V
Nominal pulse width 244 ns
Ratio of the amplitudes of positive and negative 0,95 to 1,05
pulses at the centre of the pulse interval
Ratio of the widths of positive and negative 0,95 to 1,05
pulses at the nominal half amplitude
269 ns
(244 + 25)
20%
10%
V=100% 194 ns
10%
(244 - 50)
20%
Nominal pulse
50%
244 ns
219 ns
(244 - 25)
10% 10%
10% 10%
20%
488 ns
(244 + 244)
Figure 2: Pulse mask for 2 048 kbit/s pulse
Test: The test shall be conducted according to subclause A.2.2.
4.2.1.3 Output timing

Justification: A certain level of timing accuracy is necessary for the bit stream to be received correctly at

the input to the NTP, otherwise the leased line will not achieve frame alignment and possibly send AIS

forward within the network; therefore a requirement on output timing should be included for interworking

with the network (article 4f). An output clock accuracy of 2 048 kbit/s ± 50 parts per million (ppm) is

sufficient for the input signal to be received correctly although this may result in a number of slips.

Requirement: In the absence of any external reference signal timing, the output signal shall have a bit

rate within the limits of 2 048 kbit/s ± 50 ppm.
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Test: The test shall be conducted according to subclause A.2.3.
4.2.1.4 Output jitter

Justification: A high level of jitter causes error reports within some networks, therefore this requirement

is included to prevent harm to the network, (article 4d). It is necessary for the output signals from the

terminal equipment to be received correctly at the input to the NTP, otherwise the leased line will not

achieve frame alignment and possibly send AIS forward within the network; therefore a requirement on

output jitter should be included for interworking with the network (article 4f).

Requirement: The peak-to-peak output jitter shall not exceed the limits of table 2 when measured with a

bandpass filter with linear cut-off with the defined cut-off frequencies. At frequencies below the lower 3 dB

point, the attenuation of the high pass filter shall rise with a value equal to 20 dB per decade. At

frequencies above the upper 3 dB point, the attenuation of the low pass filtration shall rise with a value

greater than, or equal to, 60 dB per decade.

For the purpose of testing, any signal input from which the output timing is derived shall be provided with

the maximum tolerable input jitter, and with the maximum tolerable input frequency deviation, as specified

by the manufacturer.

Where the output timing of the terminal equipment is taken from the leased line, the input to the terminal

equipment shall be provided with components of sinusoidal jitter at points on the curve of table 3 and

figure 3.

NOTE: A separate requirement for output jitter at frequencies below 40 Hz is not required

because the measurement filter with a first order lower cut-off will allow the jitter to

have a spectrum whose amplitude rises at 20 dB/decade as the frequency reduces

below 40 Hz. Where timing is taken from the leased line, the test uses input jitter

frequencies from 20 Hz upwards.
Table 2: Maximum output jitter
Measurement filter bandwidth Output jitter
Lower cut-off Upper cut-off Unit Interval (UI) peak-to-peak
(high pass) (low pass) (maximum)
40 Hz 100 kHz 0,11 UI
Table 3: Input jitter for output jitter measurement
Peak-to-peak amplitude (UI) Frequency (Hz)
A1 A2 f1 f2 f3 f4
1,5 0,2 20 2 400 18 000 100 000
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peak-to-peak jitterpeak-to-peak jitter
A1A1
A2A2
f1f1 f2f2 f3f3 f4f4
jitter frequencyjitter frequency
Figure 3: Input jitter for output jitter measurement
Test:
The test shall be conducted according to subclause A.2.4.
4.2.1.5 Output structure

Justification: It is necessary for the output signals from the terminal equipment to be received correctly at

the input to the NTP, otherwise the leased line will not achieve frame alignment and possibly send AIS

forward within the network; therefore a requirement on the output structure should be included for

interworking with the network (article 4f).
Requirement:

The bit stream transmitted at the output of the terminal equipment shall be structured as

defined in clause C.1.
Test:
The test shall be conducted according to subclause A.2.5.
4.2.1.5.1 CRC-4
Justification:

It is necessary for the CRC-4 from the terminal equipment to be correct at the output from

the terminal equipment, otherwise the occurrence of · 915 errored SMFs will cause the leased line to

believe that frame alignment is lost and possibly send AIS forward within the network; therefore a

requirement on the CRC-4 should be included for interworking with the network (article 4f).

Requirement:

The CRC-4 bits transmitted at the output of the terminal equipment shall be as defined in

tables C.1 and C.2 and subclause C.2.1 of annex C and shall correspond to the data transmitted at the

output of the terminal equipment.
Test: The test shall be conducted according to subclause A.2.5.
4.2.1.5.2 Use of the E-bits
There is no requirement on the use of the E-bits within this TBR.

Justification: The E-bits received at the NTP indicate errors that have occurred in the bit stream from the

NTP to the terminal equipment. The connection standard for the D2048S leased line (ETS 300 419) does

not require the network to take any action as a result of receiving an indication of errors, therefore, there

should be no requirement on the E-bits at the output from the terminal equipment.

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4.2.1.5.3 Use of the A-bit

Justification: Although the connection standard for the D2048S leased line (ETS 300 419) does not

require the network to take any action as a result of receiving an alarm indication (A = 1), there are many

networks that will respond, either at the NTP or within the network, to an input signal indicating an alarm

indication. Therefore, to ensure no harm to the network (article 4d) and correct interworking, i.e. continued

transmission, (article 4f) the terminal equipment should ensure that the alarm indication is not sent when

correct frames are received at the input.

NOTE: This requirement does not impose any essential requirement on the input port of the

terminal equipment, or any requirement to monitor the input bit stream for loss of

signal. The requirement can be met with the A-bit permanently set to A = 0.

Requirement: When the input signal to the terminal equipment comprises continuous error free frames

and multiframes, structured according to annex C, with the calculated CRC-4 corresponding to the data in

the previous SMF, the A-bit at the output of the terminal equipment shall be set to binary ZERO.

Test: The test shall be conducted according to subclause A.2.5.
4.2.1.5.4 Use of the S bits
There is no requirement on the use of the S bits within this TBR.

Justification: Bits S to S are reserved for the use of the leased line operator and these are not

a4 a8

necessarily transmitted transparently across the connection. Therefore there is no harm to the network

(article 4d) or failure to interwork (article 4f) caused by any potential setting of these bits.

4.2.2 Input port

There are no requirements on the input port under this TBR beyond those imposed in subclauses 4.4.1 to

4.4.3.

Justification: The requirements imposed on the terminal equipment output port do not require the correct

receipt of data at the terminal equipment input port. The network output port is protected against both

short circuit and open circuit. Therefore there are no requirements within the base st

...

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