SIST I-ETS 300 465 E1:2003
(Main)Broadband Integrated Services Digital Network (B-ISDN); Availability and retainability performance for B-ISDN semi-permanent connections
- Abstract
Specification of performance parameters for availability and retainability of semi-permanent connection types
- Status
- Published
- Publication Date
- 30-Nov-2003
- Current Stage
- 6060 - National Implementation/Publication (Adopted Project)
- Start Date
- 01-Dec-2003
- Due Date
- 01-Dec-2003
- Completion Date
- 01-Dec-2003
SIST I-ETS 300 465 E1:2003 is a SIST standard aligned with ETSI I-ETS 300 465 for Broadband Integrated Services Digital Network (B-ISDN) semi-permanent connections. It specifies how to describe and measure availability and retainability performance for B-ISDN semi-permanent connection portions, so network operators, engineers and test teams can assess virtual path connections (VPCs) and virtual channel connections (VCCs).
What does SIST I-ETS 300 465 E1:2003 specify?
SIST I-ETS 300 465 E1:2003 specifies performance parameters for availability and retainability of B-ISDN semi-permanent connections. It focuses on how to define the down state, how to estimate unavailability and outage behavior, and how to use those definitions for long-term performance assessment.
The scope covers B-ISDN semi-permanent connections, including VPCs and VCCs. For international connections, the document explains that the connection is partitioned into two national portions and an international portion, and that the international portion is further divided into connection portions delimited by International Measurement Points (MPI) as defined in prI-ETS 300 464.
The document is organized into five clauses and four informative annexes.
| Annex | What it covers |
|---|---|
| Annex A | Example observation method for Severely Errored Second (SES) |
| Annex B | Related B-ISDN semi-permanent connection dependability parameters |
| Annex C | Guidance for compliance testing for availability and retainability performance |
| Annex D | Bibliography |
What are the key requirements of SIST I-ETS 300 465 E1:2003?
SIST I-ETS 300 465 E1:2003 is mainly a measurement and definition document. It tells readers how to recognize availability states, how to compute the two specified dependability parameters, and how to approach compliance testing.
Clause 4 defines the state model
Clause 4 says the decision parameters for the down state are based on a subset of the performance parameters from prI-ETS 300 464. In practice, this means the operator must observe agreed performance measures over defined time windows and use them to decide when a connection portion is available or unavailable.
Clause 4.1 defines the unavailable-state entry and exit criterion using Severely Errored Second (SES) outcomes. An SES occurs when a one-second interval contains an interruption that prevents cell transfer, or when the cell transfer performance parameters for that second exceed the relevant threshold. The interruption is tied to the physical layer or the Asynchronous Transfer Mode (ATM) layer, not to user action.
Clause 4 defines when a connection becomes unavailable
A period of unavailable time begins when SES continues for ten consecutive seconds. A period of available time begins with the first second of ten consecutive seconds in which none of the seconds are SES. For a bidirectional B-ISDN connection, both directions must be available.
In practice, this gives a clear rule for counting downtime. That matters because availability is not just a general quality claim - it is tied to a specific sequence of second-by-second observations.
Clause 4 defines the two performance parameters
Clause 4.2 defines asymptotic unavailability and outage intensity. Asymptotic unavailability is estimated as the ratio of total accumulated unavailable time to the observation period. Outage intensity is estimated as the number of unavailable periods divided by the observation period.
These definitions matter because they turn observed network behavior into values that can be compared, trended and used in compliance testing. Annex B then links these parameters to MTBO, MTTR, asymptotic availability and retainability.
Clause 5 separates objectives from definitions
Clause 5 says performance objectives will be defined in a later version of the I-ETS. It also states that compliance with those objectives is the responsibility of each network operator, with guidance for testing given in Annex C. In practice, the standard sets the method for assessment before the target values are introduced.
What terms does SIST I-ETS 300 465 E1:2003 define?
- Severely Errored Second (SES) - a one-second interval used to mark the start or continuation of an unavailable state.
- Severely Errored Cell Block (SECB) - in Annex A, a block used as an example input for deciding SES outcomes.
- Operation Administration and Maintenance (OAM) - the monitoring cell flows used in Annex A to observe service behavior.
- International Measurement Point (MPI) - a boundary point used to delimit connection portions in international B-ISDN semi-permanent connections.
- Mean Time Between Outages (MTBO) - the average duration of continuous available intervals between outages.
- Mean Time To Restore (MTTR) - the average duration of continuous unavailable intervals.
- Alarm Indication Signal (AIS) - an OAM signal whose reception can trigger an SES outcome in the Annex A example.
- Asynchronous Transfer Mode (ATM) - the transfer mode whose layer behavior is referenced when defining interruptions.
Who uses SIST I-ETS 300 465 E1:2003?
SIST I-ETS 300 465 E1:2003 is used by network operators, transmission planners, quality and reliability engineers, and compliance test teams working with B-ISDN semi-permanent connections. It is also relevant to organizations managing OAM monitoring, because the document ties availability assessment to observed network behavior.
It is useful when defining how to measure connection availability, how to classify outages, and how to prepare compliance testing for VPCs and VCCs.
What changed in SIST I-ETS 300 465 E1:2003 from the previous edition?
SIST I-ETS 300 465 E1:2003 is identical to I-ETS 300 465 Edition 1. The document history identifies that edition as the First Edition from February 1996.
Which standards are used with SIST I-ETS 300 465 E1:2003?
- I-ETS 300 464 - provides the ATM layer cell transfer performance parameters and the MPI-based partitioning referenced in the scope and definitions.
- ITU-T Recommendation I.610 - provides B-ISDN operation and maintenance principles and functions, including the layer interpretation of interruptions and the OAM-AIS behavior used in Annex A.
- ITU-T Recommendation E.800 - provides terms and relationships for quality of service and network performance, including dependability.
- ITU-T Recommendation I.150 - is cited in Annex B for the directionality of ATM connections.
- ITU-T Recommendation I.350 - appears in the bibliography for general quality of service and network performance concepts.
- IEC Publication 1170 - is used in Annex C for compliance test procedures for steady-state availability.
- IEC Publication 1124 - is used in Annex C for compliance test plans for constant failure rate and constant failure intensity.
What does the SIST I-ETS 300 465 E1:2003 document contain?
SIST I-ETS 300 465 E1:2003 contains definitions, state criteria and performance parameter descriptions rather than target values. It gives the logic for SES-based unavailable-state detection, the long-term concepts behind asymptotic unavailability and outage intensity, and the way these relate to other dependability measures.
Annex A provides an example observation method based on OAM monitoring, SECB outcomes, OAM-AIS cells and continuity check cells. Annex B gives relationships among U, λ, A, MTBO, MTTR and retainability R. Annex C explains how compliance testing should be approached using statistical methods and the IEC references.
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Frequently Asked Questions
SIST I-ETS 300 465 E1:2003 is a standard published by the Slovenian Institute for Standardization (SIST). Its full title is "Broadband Integrated Services Digital Network (B-ISDN); Availability and retainability performance for B-ISDN semi-permanent connections". This standard covers: Specification of performance parameters for availability and retainability of semi-permanent connection types
Specification of performance parameters for availability and retainability of semi-permanent connection types
SIST I-ETS 300 465 E1:2003 is classified under the following ICS (International Classification for Standards) categories: 33.080 - Integrated Services Digital Network (ISDN). The ICS classification helps identify the subject area and facilitates finding related standards.
SIST I-ETS 300 465 E1:2003 is available in PDF format for immediate download after purchase. The document can be added to your cart and obtained through the secure checkout process. Digital delivery ensures instant access to the complete standard document.
Standards Content (Sample)
SLOVENSKI STANDARD
01-december-2003
Širokopasovno digitalno omrežje z integriranimi storitvami (B-ISDN) –
Razpoložljivost in obseg obdržljivosti za polstalne zveze v B-ISDN
Broadband Integrated Services Digital Network (B-ISDN); Availability and retainability
performance for B-ISDN semi-permanent connections
Ta slovenski standard je istoveten z: I-ETS 300 465 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.
INTERIM
EUROPEAN I-ETS 300 465
TELECOMMUNICATION February 1996
STANDARD
Source: ETSI TC-NA Reference: DI/NA-042129
ICS: 33.020, 33.080
B-ISDN, availability, performance
Key words:
Broadband Integrated Services Digital Network (B-ISDN);
Availability and retainability performance
for B-ISDN semi-permanent connections
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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I-ETS 300 465: February 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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I-ETS 300 465: February 1996
Contents
Foreword .5
Introduction.5
1 Scope .7
2 Normative references.7
3 Symbols and abbreviations .7
4 Definition of parameters .7
4.1 Definition of entry/exit criterion for the unavailable state .8
4.1.1 Definition of SES .8
ATM
4.1.2 Definition of the unavailable state .8
4.2 Specified parameters.8
4.2.1 Asymptotic unavailability .8
4.2.2 Outage intensity.9
5 Performance objectives.9
Annex A (informative): Example of observation method for SES .10
ATM
Annex B (informative): Related B-ISDN semi-permanent connection dependability parameters.11
Annex C (informative): Guidance for compliance testing for availability and retainability performance.12
Annex D (informative): Bibliography.13
History.14
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I-ETS 300 465: February 1996
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I-ETS 300 465: February 1996
Foreword
This Interim European Telecommunication Standard (I-ETS) has been produced by the Network Aspects
(NA) Technical Committee of the European Telecommunications Standards Institute (ETSI).
An ETSI standard may be given I-ETS status either because it is regarded as a provisional solution ahead
of a more advanced standard, or because it is immature and requires a "trial period". The life of an I-ETS
is limited to three years after which it can be converted into an ETS, have it's life extended for a further
two years, be replaced by a new version, or be withdrawn.
Proposed announcement date
Date of adoption of this I-ETS: 16 February 1996
Date of latest announcement of this I-ETS (doa): 31 May 1996
Introduction
From an availability and retainability point of view, a portion of a Broadband Integrated Services Digital
Network (B-ISDN) semi-permanent connection should have the following properties:
- unavailability
The unavailability of a B-ISDN semi-permanent connection portion is the fraction of time during
which it cannot accommodate a transaction (i.e. it is in a down state). This down state is to be
characterized by a set of decision parameters, specific to the information transfer phase, and their
associated outage criteria.
The fraction of time during which it is in a down state should be as low as possible;
- retainability
The retainability performance of B-ISDN semi-permanent connection portions is defined in this
I-ETS as the probability that a transaction using a B-ISDN semi-permanent connection portion once
obtained (i.e. is available), will neither be interrupted nor prematurely released (i.e. does not
become unavailable) for a given duration. In this I-ETS the retainability performance is specified in
terms of outage intensity.
Once a transaction is started on a B-ISDN semi-permanent connection, it should have a low
probability of being either interrupted (because of insufficient data transfer performance) or
prematurely released (due to the failure of some network component) before the requested end of
the transaction.
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I-ETS 300 465: February 1996
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I-ETS 300 465: February 1996
1 Scope
This Interim European Telecommunication Standard (I-ETS) specifies availability and retainability
parameters for Broadband Integrated Services Digital Network (B-ISDN) semi-permanent connections
(VPCs and VCCs)
An international B-ISDN semi-permanent connection is partitioned into two national portions and an
international portion. The international portion is further partitioned into connection portions delimited by
International Measurement Points (MPIs) as defined in prI-ETS 300 464 [1].
A futur version of this I-ETS will specify objectives for the availability and retainability performance of each
of these portions, and measurement methods will be defined.
2 Normative references
This I-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 I-ETS only when incorporated in it by amendment or revision. For undated references the
latest edition of the publication referred to applies.
[1] I-ETS 300 464: "Asynchronous Transfer Mode (ATM); Broadband Integrated
Services Digital Network (B-ISDN); ATM layer cell transfer performance for
B-ISDN connection types".
[2] ITU-T Recommendation I.610 (1994): "B-ISDN operation and maintenance
principles and functions".
[3] ITU-T Recommendation E.800 (1994):."Terms and definitions related to quality
of service and network performance including dependability".
3 Symbols and abbreviations
For the purposes of this I-ETS, the following abbreviations apply:
AIS Alarm Indication Signal
ATM Asynchronous Transfer Mode
FS Frontier Station
ISC International Switching Center
MPI International Measurement Point
MTBO Mean Time Between Outages
MTTR Mean Time To Restore
OAM Operation Administration and Maintenance
SECB Severely Errored Cell Block
SES Severely Errored Second
ATM
4 Definition of parameters
The decision parameters which characterize the down state of a B-ISDN semi-permanent connection
portion are based on a subset of the performance parameters defined in prI-ETS 300 464 [1].
NOTE: It is likely that CLR and SECBR will be the parameters that form this subset.
The observation process of these decision parameters will include the specification of time during which
they are estimated. It is necessary to base the outage criteria for the unavailable state on successive
observations of decision parameters.
In order to classify available and unavailable states, entry/exit criteria are defined.
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