SIST ETS 300 818 E1:2003

• Abstract:

  To define netowrk performance parameters for B-ISDN connection types from the retainability point of view.

• Status: Published
• Publication Date: 30-Nov-2003
• ICS: 33.080 - Integrated Services Digital Network (ISDN)
• Technical Committee: SS EIT - Technical Board for the electrotechnical, information technology and telecommunications fields
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 01-Dec-2003
• Due Date: 01-Dec-2003
• Completion Date: 01-Dec-2003
• Ref Project: ETSI ETS 300 818 ed.1 (1998-09) - Broadband Integrated Services Digital Network (B-ISDN); Asynchronous Transfer Mode (ATM); Retainability performance for B-ISDN switched connections

SIST ETS 300 818 E1:2003 is the Slovenian adoption of ETS 300 818 Edition 1, an ETSI European Telecommunication Standard for Broadband Integrated Services Digital Network (B-ISDN) Asynchronous Transfer Mode (ATM) switched connections. It specifies retainability parameters and measurement methods for point-to-point B-ISDN ATM switched connections, so operators can assess how often established connections stay up without cut-off.

What does SIST ETS 300 818 E1:2003 specify?

SIST ETS 300 818 E1:2003 defines retainability from the network-performance point of view for B-ISDN point-to-point ATM switched connections. It explains how connections are divided into portions for measurement, and it points to a later version for numerical objectives for those portions.

The document is organized into clauses on scope, normative references, abbreviations, introduction, connection portions, retainability parameters, and retainability performance objectives, followed by two normative annexes.

Annex	What it covers
Annex A	Measurement and compliance testing for retainability performance
Annex B	Calculation of end-to-end retainability performance

What are the key requirements of SIST ETS 300 818 E1:2003?

The standard focuses on how to define, measure, and combine retainability for B-ISDN ATM switched connections.

Connection portions and measurement boundaries

Clause 5 splits an international B-ISDN ATM switched connection into National Portions (NPs), International Transit Portions (ITPs), and International Inter-operator Portions (IIPs). These portions are delimited by Measurement point at the T interface (MPT) points or International Measurement Points (MPIs). In practice, this means performance is assessed on standardized pieces of the connection, not only on the whole route.

What counts as a cut-off

Clause 6.1 defines a cut-off event as either 10 consecutive Severely Errored Seconds in the ATM layer (SES) or a premature release. A premature release is a release caused by a switch or cross-connect that is not the result of a user request. This matters because retainability is not just about user disconnections - it also covers network-caused loss of an established connection.

How retainability is expressed

Clause 6.2 defines cut-off rate as the instantaneous rate at which a connection portion reaches cut-off, and clause 6.3 defines retainability R as the probability that a connection portion not cut off at time 0 will remain connected up to time t. When the cut-off rate is assumed constant, the document gives an exponential relationship between retainability, time, and cut-off rate. In practice, this gives operators a way to turn observed failures into a performance figure.

How compliance is checked

Annex A says cut-off rate is estimated from the number of cut-off events observed across a set of similar connection portions divided by their accumulated operating time. The observed value is treated as an estimate of the true value, and compliance testing compares that estimate with limits. This is the basis for field measurements and acceptance checks.

How end-to-end performance is derived

Annex B gives guidance for calculating end-to-end retainability for an international switched ATM connection from the retainability of its portions. Under the stated assumption that protection cannot act quickly enough, the end-to-end cut-off rate is the sum of the portion cut-off rates, and end-to-end retainability is the product of the portion retainabilities. That is useful when a carrier needs one overall result from several network segments.

What terms does SIST ETS 300 818 E1:2003 define?

• B-ISDN - Broadband Integrated Services Digital Network, the service environment covered by the standard.
• ATM - Asynchronous Transfer Mode, the transfer technique used for the switched connections.
• NP - National Portion, the part of an international connection within one country.
• ITP - International Transit Portion, the part that carries traffic through transit networks.
• IIP - International Inter-operator Portion, the part between operators in the international portion.
• MPI - International Measurement Point, a boundary used to delimit connection portions for measurement.
• SES - Severely Errored Second in the ATM layer, the error condition used in the cut-off definition.

Who uses SIST ETS 300 818 E1:2003?

SIST ETS 300 818 E1:2003 is used by network operators, performance engineers, and quality or compliance teams working on B-ISDN ATM switched connections. They use it to define what to measure, estimate cut-off rates from field data, and evaluate retainability for individual connection portions and end-to-end routes.

Which standards are used with SIST ETS 300 818 E1:2003?

The standard relies on three normative references:

• ITU-T Recommendation I.353 - provides the reference events for defining ISDN and B-ISDN performance parameters.
• I-ETS 300 465 - provides the definition of the SES outcome used in the cut-off event definition.
• ITU-T Recommendation I.356 - provides B-ISDN ATM layer cell transfer performance and the definitions of connection portions and measurement points used here. The standard notes that I.356 is used instead of the ETSI equivalent I-ETS 300 464 because it contains information not yet incorporated there.

What does the SIST ETS 300 818 E1:2003 document contain?

SIST ETS 300 818 E1:2003 contains the scope, reference list, abbreviations, and an introduction that explains the two causes of cut-off: 10 consecutive SES or premature release. It then defines connection portions, cut-off rate, and retainability, including the probability-based and exponential relationship used for analysis.

The two normative annexes provide the practical parts of the standard. Annex A describes how to estimate cut-off rate and test compliance, while Annex B shows how to derive end-to-end retainability from the retainability of standardized portions.

SLOVENSKI STANDARD
01-december-2003
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Broadband Integrated Services Digital Network (B-ISDN); Asynchronous Transfer Mode
(ATM); Retainability performance for B-ISDN switched connections
Ta slovenski standard je istoveten z: ETS 300 818 Edition 1
ICS:
33.080 Digitalno omrežje z Integrated Services Digital
integriranimi storitvami Network (ISDN)
(ISDN)
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN ETS 300 818
TELECOMMUNICATION September 1998
STANDARD
Source: NA Reference: DE/NA-042123
ICS: 33.020
Key words: B-ISDN, ATM, retainability, performance
Broadband Integrated Services Digital Network (B-ISDN);
Asynchronous Transfer Mode (ATM);
Retainability performance for B-ISDN switched connections
ETSI
European Telecommunications Standards Institute
ETSI Secretariat
Postal address: F-06921 Sophia Antipolis CEDEX - FRANCE
Office address: 650 Route des Lucioles - Sophia Antipolis - Valbonne - FRANCE
Internet: [e-mail] - http://www.etsi.fr - http://www.etsi.org
Tel.: [phone] - Fax: [phone]
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 1998. All rights reserved.

Page 2
ETS 300 818: September 1998
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 Standards Making Support Dept." at the address shown on the title page.

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ETS 300 818: September 1998
Contents
Foreword .5
1 Scope .7
2 Normative references.7
3 Abbreviations.7
4 Introduction.8
5 B-ISDN connection portions.8
6 Definition of Retainability parameters.8
6.1 Definition of a cut-off event .8
6.2 Cut-off rate.9
6.3 Retainability.9
7 Retainability performance objectives.9
Annex A (normative): Measurement and compliance testing for retainability performance.10
Annex B (normative): Calculation of end-to-end retainability performance.11
History.12

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ETS 300 818: September 1998
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ETS 300 818: September 1998
Foreword
This European Telecommunication Standard (ETS) has been produced by the Network Aspects (NA)
Technical Committee of the European Telecommunications Standards Institute (ETSI).
Transposition dates
Date of adoption of this ETS: 18 September 1998
Date of latest announcement of this ETS (doa): 31 December 1998
Date of latest publication of new National Standard
or endorsement of this ETS (dop/e): 30 June 1999
Date of withdrawal of any conflicting National Standard (dow): 30 June 1999

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ETS 300 818: September 1998
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ETS 300 818: September 1998
1 Scope
The purpose of this European Telecommunication Standard (ETS) is to specify retainablility parameters
and measurement methods for Broadband Integrated Services Digital Network (B-ISDN) point to point
Asynchronous Transfer Mode (ATM) switched connections.
An International B-ISDN point to point ATM switched connection is partitioned into two National Portions
(NPs), and an International Portion (IP).
The IP is further partitioned into connection portions delimited by international measurement points (MPIs)
as defined in ITU-T Recommendations I.353 [1] and I.356 [3]: International Transit Portions (ITPs) and
International Inter-operator Portions (IIPs).
A later version of this ETS will specify objectives for the retainability performance of National Portions,
International Transit Portions and International Inter-operator Portions.
It is not currently planned to specify end-to-end objectives for retainability performance. Annex B provides
guidelines for deriving end-to-end objectives from connection portion objectives.
2 Normative references
This ETS 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 ETS only when incorporated in it by amendment or revision. For undated references the latest
edition of the publication referred to applies.
[1] ITU-T Recommendation I.353: "Reference events for defining ISDN and B-ISDN
performance parameters".
[2] I-ETS 300 465: "Broadband Integrated Services Digital Network (B-ISDN);
Availability and Retainability performance for B-ISDN semi permanent
connections".
[3] ITU-T Recommendation I.356: "B-ISDN ATM layer cell transfer performance".
NOTE: ITU-T Recommendation I.356 is used as a normative reference rather than the ETSI
equivalent I-ETS 300 464, as ITU-T Recommendation I.356 contains important
information yet to be incorporated in the I-ETS 300 464. It should be noted that the
common materia
...