Business TeleCommunications (BTC); 2 048 kbit/s digital structured leased lines (D2048S); Connection characteristics

Specification of the performance requirement for the connection through the public network, including test procedures for compliance

Poslovne telekomunikacije (BTC) - Digitalni zakupljeni vodi za prenosno hitrost 2 048 kbit/s in za strukturirane signale (D2048S) - Prenosne značilnosti

General Information

Status
Published
Publication Date
31-Oct-1999
Current Stage
6060 - National Implementation/Publication (Adopted Project)
Start Date
01-Nov-1999
Due Date
01-Nov-1999
Completion Date
01-Nov-1999
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SLOVENSKI STANDARD
SIST ETS 300 419:1999
01-november-1999

3RVORYQHWHOHNRPXQLNDFLMH %7& 'LJLWDOQL]DNXSOMHQLYRGL]DSUHQRVQRKLWURVW

NELWVLQ]DVWUXNWXULUDQHVLJQDOH '6 3UHQRVQH]QDþLOQRVWL
Business TeleCommunications (BTC); 2 048 kbit/s digital structured leased lines
(D2048S); Connection characteristics
Ta slovenski standard je istoveten z: ETS 300 419 Edition 1
ICS:
33.040.50 Vodi, zveze in tokokrogi Lines, connections and
circuits
SIST ETS 300 419:1999 en

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

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SIST ETS 300 419:1999
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SIST ETS 300 419:1999
EUROPEAN ETS 300 419
TELECOMMUNICATION November 1995
STANDARD
Source: ETSI TC-BTC Reference: DE/BTC-02022
ICS: 33.040.40
ONP, leased line, D2048S, connection
Key words:
Business TeleCommunications (BTC);
2 048 kbit/s digital structured leased lines (D2048S);
Connection characteristics
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 1995. All rights reserved.
New presentation - see History box
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ETS 300 419: November 1995

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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ETS 300 419: November 1995
Contents

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

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

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

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

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

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

3.2 Abbreviations .......................................................................................................................9

4 Requirements....................................................................................................................................10

4.1 Attributes............................................................................................................................10

4.1.1 Transfer rate..................................................................................................11

4.1.1.1 Leased line timing................................................................11

4.1.1.2 Information transfer rate ......................................................11

4.1.2 Information transfer susceptance..................................................................11

4.1.3 Structure........................................................................................................12

4.1.3.1 CRC-4..................................................................................12

4.1.3.2 Use of the E-bits ..................................................................12

4.1.3.3 Frame synchronization and data transmission capability ....12
4.1.3.3.1 Multiframe alignment ............................13

4.1.3.4 Use of the A-bit....................................................................13

4.1.3.5 Use of the S bits .................................................................13

4.1.4 Establishment of connection .........................................................................13

4.1.5 Symmetry ......................................................................................................13

4.1.6 Connection configuration...............................................................................13

4.1.7 Network performance....................................................................................13

4.1.7.1 Transmission delay..............................................................13

4.1.7.2 Jitter.....................................................................................14

4.1.7.2.1 Jitter tolerance at the network input
port........................................................14
4.1.7.2.2 Maximum jitter at the network output
port........................................................15

4.1.7.3 Controlled slip......................................................................15

4.1.7.4 Error.....................................................................................16

4.1.7.4.1 Bringing Into Service (BIS) limits ..........16
4.1.7.4.2 Performance level.................................16

4.1.7.5 Availability............................................................................16

Annex A (normative): Test methods......................................................................................................17

A.1 General..............................................................................................................................................17

A.1.1 Equipment connection .......................................................................................................17

A.1.2 Sequence of performing the tests......................................................................................17

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

A.2.1 Information transfer rate, susceptance and symmetry ......................................................17

A.2.2 Delay..................................................................................................................................18

A.2.3 Jitter ...................................................................................................................................19

A.2.4 Error and slip......................................................................................................................21

A.2.5.1 Output structure and CRC-4 generation........................................................21

A.2.5.2 Use of the E-bits............................................................................................22

A.2.5.3 Frame synchronization and data transmission capability..............................23

A.2.5.4 Multiframe alignment.....................................................................................24

Annex B (normative): Definition of frame structure ...............................................................................26

B.1 Frame structure.................................................................................................................................26

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ETS 300 419: November 1995

B.2 CRC-4............................................................................................................................................... 26

B.2.1 CRC-4 generation ............................................................................................................. 26

B.2.2 CRC-4 monitoring ............................................................................................................. 27

Annex C (informative): Derivation of error performance limits ............................................................... 28

C.1 Introduction....................................................................................................................................... 28

C.2 Reference connections..................................................................................................................... 28

C.2.1 Terrestrial connection........................................................................................................ 28

C.2.2 Satellite connection ........................................................................................................... 29

C.3 Error performance objectives ........................................................................................................... 29

C.4 Long term error performance ........................................................................................................... 30

Annex D (informative): Availability .......................................................................................................... 31

D.1 General............................................................................................................................................. 31

D.1.1 Unavailability ..................................................................................................................... 31

D.1.2 Outage intensity ................................................................................................................ 31

D.1.3 Mean time between failures .............................................................................................. 31

D.1.4 Mean time to restore service............................................................................................. 31

D.2 Recommendations............................................................................................................................ 31

Annex E (informative): Bibliography ....................................................................................................... 32

History......................................................................................................................................................... 33

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ETS 300 419: November 1995
Foreword
This European Telecommunication Standard (ETS) has been produced by the Business

TeleCommunications (BTC) Technical Committee of the European Telecommunications Standards

Institute (ETSI).

This ETS resulted from a mandate from the Commission of the European Community (CEC) to provide

harmonized standards for support of the Directive on Open Network Provision (ONP) of leased lines

(92/44/EEC).
There are two other standards directly related to this ETS:

- ETS 300 418: "Business TeleCommunications (BTC); 2 048 kbit/s digital unstructured and

structured leased lines (D2048U and D2048S); Network interface presentation";

- ETS 300 420: "Business TeleCommunications (BTC); 2 048 kbit/s digital structured leased line

(D2048S); Terminal equipment interface".

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

documents are quoted where appropriate.
Transposition dates
Date of adoption of this ETS 17 November 1995
Date of latest announcement of this ETS (doa): 28 February 1996
Date of latest publication of new National Standard 31 August 1996
or endorsement of this ETS (dop/e):
Date of withdrawal of any conflicting National Standard (dow): 31 August 1996
Introduction

The Council Directive on the application of ONP to leased lines (92/44/EEC) concerns the harmonization

of conditions for open and efficient access to, and use of, the leased lines provided over 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 organizations within the EU shall make

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

and specified interfaces. Under the Second Phase Directive (91/263/EEC), terminal equipment for

connection to these leased lines will be required to fulfil certain essential requirements.

CCITT Recommendation I.340 for Integrated Services Digital Network (ISDN) connection types is used as

a basis for the connection characteristics. ETS 300 167 and CCITT Recommendations G.704 and G.706

are used as the basis for the structure.
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1 Scope

This ETS specifies the technical requirements and test principles for connection characteristics of Open

Network Provision (ONP) 2 048 kbit/s digital structured leased lines. The leased line operates at

2 048 kbit/s and provides an information transmission capability, without restriction on binary content, of

1 984 kbit/s. The remaining 64 kbit/s provides a 8 kHz framing structure in accordance with ETS 300 167

and CCITT Recommendations G.704 and G.706.

A connection is presented via interfaces at Network Termination Points (NTPs) and includes any

equipment that may provide the NTP. Signals between terminal equipments are subject to impairments

during their transfer over the connection. The limits to these impairments are stated in this ETS. Together

with the companion standard, ETS 300 418 defining the network interface presentation, this ETS

describes the technical characteristics of the leased line service offered to the user.

The tests specified in this ETS cannot be carried out by the leased line provider, while the leased line is in

service, i.e. carrying users' traffic. Thus the tests are designed for bringing into and returning into service,

although there is no obligation to perform these tests each time a leased line is brought into or returned

into service. However, because the connection is structured, the error performance may be monitored by

the leased line provider while the line is in service.

This ETS is applicable for leased lines, including part time leased lines, for which the establishment or

release does not require any protocol exchange or other intervention at the NTP.

This ETS specifies the compliance tests for the connection requirements. This ETS does not include

details concerning the implementation of the tests, nor does it include information on any relevant

regulations.
2 Normative references

This ETS incorporates by dated or 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 ETS only when incorporated into it by amendment or revision. For undated references the

latest edition of the publication referred to applies.
[1] CCITT Recommendation O.151 (1992): "Error performance measuring
equipment for digital systems at the primary bit rate and above".
[2] CCITT Recommendation O.153 (1992): "Basic parameters for the measurement
of error performance at bit rates below the primary rate".
[3] CCITT Recommendation O.171 (1992): "Timing jitter measuring equipment for
digital systems".
[4] ETS 300 418: "Business TeleCommunications (BTC); 2 048 kbit/s digital
unstructured and structured leased lines (D2048U and D2048S); Network
interface presentation".

NOTE: This ETS 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 ETS, the following definitions apply:

Background Block Error (BBE): An errored block not occurring as part of a Severely Errored Second

(SES).

BBE ratio: The ratio of errored blocks to total blocks during a fixed measurement interval excluding all

blocks during severely errored seconds and while the leased line connection is in the unavailable state

(see ITU-T Recommendation G.826).

block: A set of 2 048 consecutive bits equivalent to one Sub-MultiFrame (SMF). Each block is monitored

by means of a Cyclic Redundancy Check-4 bit (CRC-4) error check. The length of each block

corresponds to a period of 1 ms.

NOTE: This definition is relevant only to this ETS and is more specific than the generic

definition given in ITU-T Recommendation G.826.

controlled slip: The irretrievable loss or gain of a set of consecutive digit positions in a digital signal, in

which both the magnitude and instant of that loss or gain are controlled, to enable the signal to accord with

a rate different from its own.

errored block: A block in which one or more bits are in error (see ITU-T Recommendation G.826).

Errored Second (ES): A one-second period with one or more errored blocks (see ITU-T

Recommendation G.826).

ES ratio: The ratio of ES to total seconds during a fixed measurement interval. The ES ratio is not

evaluated while the leased line connection is in the unavailable state (see ITU-T Recommendation G.826).

errored Sub-MultiFrame: A Sub-MultiFrame (SMF) where the calculated CRC-4 does not correspond

with the CRC-4 contained within the next SMF (see subclause B.2.2).

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

frame slip: A slip of one complete frame.

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 B).

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): A Pseudo Random Bit Sequence (PRBS) (as defined in subclause 2.1 of CCITT

Recommendation O.153 [2]).

PRBS(2 -1): A PRBS (as defined in subclause 2.1 of CCITT Recommendation O.151 [1]).

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

a4 a8
satellite transmission: A transmission via an earth orbiting satellite.

severely disturbed period: For out-of-service measurements, a severely disturbed period occurs when,

over a period of time equivalent to four contiguous blocks, either all the contiguous blocks are affected by

a high bit error density of = 10 , or a loss of signal is observed. For in-service monitoring purposes, a

severely disturbed period is estimated by the occurrence of loss of signal or loss of frame alignment (see

ITU-T Recommendation G.826).
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Severely Errored Second (SES): A one-second period which contains = 805 errored blocks or at least

one severely disturbed period (see ITU-T Recommendation G.826).

SES ratio: The ratio of SES to total seconds during a fixed measurement interval. The SES ratio is not

evaluated while the leased line connection is in the unavailable state (see ITU-T Recommendation G.826).

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

(see annex B).

uncontrolled slip: The loss or gain of a digit position or a set of consecutive digit positions in a digital

signal, resulting from an aberration of the timing processes associated with transmission or switching of a

digital signal, and in which either the magnitude or the instant of that loss or gain is not controlled.

unavailability period: An unavailability period begins at the onset of 10 consecutive SES. These 10

seconds are considered to be part of the unavailability period. The unavailability period ends at the onset

of 10 consecutive non-SES. These 10 seconds are not considered part of the unavailability period.

unavailable state: The leased line connection is in the unavailable state if an unavailability period is

occurring in one or both directions of transmission.
3.2 Abbreviations
For the purposes of this ETS, the following abbreviations apply:
BBE Background Block Error
BIS Bringing Into Service
CRC-4 Cyclic Redundancy Check-4 bit
D2048S 2 048 kbit/s digital structured ONP leased line
EMC ElectroMagnetic Compatibility
ES Errored Second
HDB3 High Density Bipolar code of order 3
NTP Network Termination Point
ONP Open Network Provision
ppm parts per million
PRBS Pseudo Random Bit Sequence
PRC Primary Reference Clock
RAI Remote Alarm Indication

RX RX is a signal input (at either the leased line interface or the test equipment)

SES Severely Errored Second
SMF Sub-MultiFrame

TX TX is a signal output (at either the leased line interface or the test equipment)

UI Unit Interval
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4 Requirements

The performance of the leased line shall comply with these requirements only if the conditions of supply of

the network equipment providing the NTP are met, (e.g. if the equipment is connected to an appropriate

power supply on the customer's premises).

The ITU-T attribute technique is used to express the connection requirements. The following attributes

from ITU-T Recommendation I.140 are specified in this ETS:
- Transfer rate;
- Information transfer susceptance;
- Structure;
- Establishment of connection;
- Symmetry;
- Connection configuration;
- Network performance.

The following network performance sub-attributes are considered relevant for this ETS:

- Transmission delay;
- Jitter;
- Slip;
- Error.
4.1 Attributes

The connection attributes are displayed in table 1. In effect, these attributes define the service being

offered.

The values and the associated compliance tests can be found in the subsequent subclauses.

Table 1: Connection attributes
Connection type attributes Value
Description Nature Reference subclause
Transfer rate
Leased line timing 2 048 kbit/s See 4.1.1.1
Information transfer rate 1 984 kbit/s See 4.1.1.2
Information transfer susceptance No restriction on binary See 4.1.2
content
Structure Frame integrity See 4.1.3
Establishment of connection Without user See 4.1.4
intervention
Symmetry Symmetrical in both See 4.1.5
directions
Connection configuration Point-to-point See 4.1.6
(continued)
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Table 1 (concluded): Connection attributes
Network performance sub-attributes
Connection type attributes Value
Description Nature Reference subclause
Transmission delay Terrestrial and satellite See 4.1.7.1
options
Jitter Input and output ports See 4.1.7.2
Slip (controlled slip) See 4.1.7.3
≤ 5 per 24 hour period
Error parameters (see 5.1.7.4) Terrestrial Satellite
End-to-end performance objectives
Errored Seconds (ES) ratio < 2,000 % < 3,120 %
Severely Errored Seconds (SES) ratio < 0,100 % < 0,156 %
Background Block Errors (BBE) ratio < 0,015 % < 0,023 %
Performance level over 24 hour period
(24 hour test limit)
Errored Seconds (ES) < 1 645 < 2 592
Severely Errored Seconds (SES) < 68 < 112
Background Block Errors (BBE) < 12 732 < 19 933
4.1.1 Transfer rate
4.1.1.1 Leased line timing
Requirement: The leased line shall either:

a) carry user timing within the range 2 048 kbit/s ± 50 parts per million (ppm); or

b) provide timing that is synchronous to the network timing; or

c) take user timing within the range 2 048 kbit/s ± 50 ppm from one input and provide this timing at

both outputs of the leased line.

NOTE 1: In case b), network timing is timing that is derived from the source or sources of timing

that are used for the network. Thus the timing provided by the leased line will be

similar to that provided by other digital services.

NOTE 2: When the timing in both directions is not synchronous, the number of transmitted

E-bits differs from the number of received SMFs. As a consequence, either some valid

E-bits are lost or meaningless E-bits are inserted.

Test: There is no specific test; the leased line provider shall declare which type of timing the leased line

provides and this shall be taken into account during the subsequent tests defined in annex A.

4.1.1.2 Information transfer rate

Requirement: The connection shall be capable of transferring a nominal information rate of 1 984 kbit/s

which is contained within the frame structure defined for the leased line (see subclause 4.1.3).

Test: The test shall be conducted according to subclause A.2.1.
4.1.2 Information transfer susceptance

Requirement: The connection shall be capable of transferring digital information with bit sequence

integrity, and without restriction on binary content, at the nominal rate of 1 984 kbit/s within the defined

frame structure (see subclause 4.1.3).
Test: The test shall be conducted according to subclause A.2.1.
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4.1.3 Structure

The purpose of the structure is to allow the leased line provider to monitor the error performance of the

leased lines from NTP to NTP. The CRC-4 is, therefore, not necessarily transmitted transparently from

NTP to NTP; it may be updated by the leased line provider to determine the location of errors. In order to

allow the terminal equipment to monitor the integrity of the path between the terminal equipment and the

NTP, the NTP is required to provide a correct CRC-4, and to respond correctly with the E-bits in the event

of an incorrectly received CRC-4.

Requirement: For each direction of transmission, the leased line shall accept an input bit stream with a

frame and multiframe structure as defined in annex B. When the leased line input has the above frame

structure and the connection is not in the unavailable state, the output of the leased line shall also conform

to the frame and multiframe structure defined in annex B, with the structure having the same relationship

to the information transferred as at the input, maintaining the frame structure integrity.

Test: The test shall be conducted according to subclauses A.2.1 and A.2.5.1.
4.1.3.1 CRC-4

Requirement: At each NTP, the CRC-4 bits transmitted in the output bit stream shall be as defined in

tables B.1 and B.2 for a complete CRC-4 multiframe and shall correspond to the data transmitted at the

output of the leased line interface, (i.e. the CRC-4 shall be recalculated in the equipment providing the

NTP).
Test: The test shall be conducted according to subclause A.2.5.1.
4.1.3.2 Use of the E-bits

Requirement: At each NTP, the E-bits transmitted in the output bit stream shall indicate errored SMFs in

the input bit stream at that NTP. One E-bit in each multiframe shall be set to binary ZERO for each errored

SMF received in the input bit stream. The E-bits corresponding to non-errored SMFs shall be set to binary

ONE. Any delay between the detection of an errored SMF and the setting of the E-bit that indicates the

errored SMF shall be less than 1 second.

NOTE: The intention is that the CRC-4 verification, and the associated generation of the

E-bits, will be performed in the equipment that provides the NTP in order to indicate

only those errors that have occurred between the terminal equipment and the NTP and

not those errors that have occurred within the network.
Test: The test shall be conducted according to subclause A.2.5.2.
4.1.3.3 Frame synchronization and data transmission capability

Requirement: The leased line shall continue to transparently transmit data in the event of receiving one

or two consecutive incorrect frame alignment signals. On receipt of:
- three consecutive incorrect frame alignment signals; or
- there being = 915 errored SMFs out of 1 000 SMFs,

the leased line shall consider frame alignment to have been lost and initiate a search for frame alignment

during which time the leased line may cease transparent transmission of data.

NOTE: Some implementations may also consider frame alignment to have been lost in the

event that bit 2 in frames not containing the frame alignment signal is in error on three

consecutive occasions. This situation is unlikely to occur except in the event of high

error rates between the terminal equipment and the NTP.
Frame alignment shall not be considered as having been regained until:
a) for the first time, the presence of the correct frame alignment signal; and

b) the absence of the frame alignment signal in the following frame detected by verifying that bit 2 of

the basic frame is a binary ONE; and

c) for the second time, the presence of the correct frame alignment signal in the next frame,

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in which case transparent transmission of
...

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