SIST ETS 300 251 E1:2003
(Main)Network Aspects (NA); Accessibility for 64 kbit/s circuit switched international end-to-end ISDN traffic relations
- Abstract
This standard will specify the accessability of international end-to- end circuit switched 64 kbit/s traffic relations between T-reference points. The standard will not cover blocking at the user network interface nor catastrophic situations e.g. earthquakes, Floods etc.
- 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 ETS 300 251 E1:2003 is the Slovenian adoption of ETS 300 251 Edition 1 from ETSI. It specifies accessibility for international end-to-end circuit-switched 64 kbit/s ISDN traffic relations between T reference points. In practice, it gives network designers, operators and test labs a way to assess whether connection attempts succeed within the required time and with the required short-term access performance.
What does SIST ETS 300 251 E1:2003 specify?
SIST ETS 300 251 E1:2003 specifies the accessibility of international end-to-end circuit-switched 64 kbit/s ISDN traffic relations between T reference points. It is organized into a foreword, clauses 1 to 8, two figures for the accessibility measure and its mask, and a history section.
The scope excludes blocking at the user-network interface and catastrophic situations such as earthquakes and floods. The scope note also says the ETS may be used for design purposes.
Clause overview:
- Clause 1 - Scope
- Clause 2 - Normative references
- Clause 3 - Definitions
- Clause 4 - Symbols and abbreviations
- Clause 5 - Explicit definition for a measure for accessibility performance
- Clause 6 - Requirements
- Clause 7 - Success criteria for connection attempts
- Clause 8 - Evaluation of the NP measure for accessibility
What are the key requirements of SIST ETS 300 251 E1:2003?
SIST ETS 300 251 E1:2003 turns accessibility into a measurable network performance objective. The key idea is to look both at long-term success probability and at how often short periods of time still allow a call to get through.
Accessibility is measured with STA
Clause 5 defines Short Term Accessibility (STA) as the proportion of a time interval T during which an additional call is possible within the specified delay. The standard fixes T at 5 minutes. This matters because repeated call attempts are affected by short bursts of congestion or faults, not just by the long-term average.
The objective combines a long-term average and a distribution mask
Clause 6 requires, for all time-consistent one-hour intervals, an average access probability of at least 0.96. It also requires the actual STA distribution to stay below the mask shown in Figure 2. In practice, this means a network must not only average well over time - it must also avoid too many short periods with poor access.
Lack of B channels is treated separately
Clause 6 says blocking at the T reference point due to lack of B channels is not included in the objective. This is important when judging results, because the standard focuses on accessibility effects from traffic load, faults and similar network conditions, not on that specific capacity shortage.
Successful connection attempts have time limits
Clause 7 gives the success criteria for a connection attempt. Before dialling, the activation time of layer 1 and the establishment delay of layer 2 must meet the stated limits. After dialling, the connection set-up delay must also stay within the limit. For users and testers, this is the rule set for deciding whether a call attempt counts as successful.
Measurement is tied to specific reference events and one measurement point
Clause 7 uses reference events from ETS 300 297 and ETR 044, and it says the measurement should be performed at a single measurement point, MPT1. That gives labs and operators a common timing basis, so different measurements can be compared.
Evaluation can use traffic data or test traffic
Clause 8 says STA samples are obtained by counting successful and total connection attempts over successive T intervals. The standard allows real traffic, additional test traffic, or estimation from operational data such as equipment availability and traffic results. This matters because it gives practical ways to evaluate networks even when rare failure conditions are hard to observe.
What terms does SIST ETS 300 251 E1:2003 define?
- Accessibility performance - the ability of a network to provide a connection within a specified delay when a correct request is received at the T interface.
- Accessibility - the measure used for accessibility performance; Clause 5 gives its explicit definition.
- Measure - a function or quantity used to describe a random variable or random process.
- Short Term Accessibility (STA) - the accessibility measure defined over the interval T and used to reflect repeated connection attempts.
- NP - Network Performance, the performance view used throughout the standard.
- MPT1 - Measurement Point 1, the single point used for the success-criteria measurement.
- SABME - Set Asynchronous Balanced Mode Extended, an abbreviation listed in Clause 4.
- UA - Unnumbered Acknowledgement, an abbreviation listed in Clause 4.
Who uses SIST ETS 300 251 E1:2003?
SIST ETS 300 251 E1:2003 is used by ISDN network designers, network operators and conformance test teams. The document supports design decisions, performance assessment and compliance testing for international circuit-switched 64 kbit/s traffic relations. It is also relevant to people who measure call setup delay and interpret accessibility results against a common objective.
Which standards are used with SIST ETS 300 251 E1:2003?
| Reference | What it contributes |
|---|---|
| Supplement No. 6 to CCITT E series Recommendations | Terms and definitions for quality of service, network performance, dependability and trafficability studies; also the source for the definition of “measure”. |
| ETR 044 | Reference events for network performance parameters in an ISDN, used for layer 2 timing references. |
| DE/NA-042104 | Network performance objectives for circuit-switched connection processing delays in an ISDN, used for connection set-up delay. |
| ETS 300 297 | Access Digital Section for ISDN basic rate, used for layer 1 activation and layer 2 establishment timing references. |
| DI/NA-042117 | Conformance test specification for this accessibility standard, used for compliance testing. |
What does the SIST ETS 300 251 E1:2003 document contain?
SIST ETS 300 251 E1:2003 contains a conceptual definition of the STA measure, including Figure 1, which illustrates how STA is formed over the interval T. It also contains the accessibility objective and Figure 2, which shows the mask used to judge the distribution of STA values.
Table 1 gives the success criteria for connection attempts, linked to reference event codes and timing limits. Clause 8 describes how to evaluate the NP measure from observed or test connection attempts, and it also mentions using operational data as an alternative route to estimation.
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Frequently Asked Questions
SIST ETS 300 251 E1:2003 is a standard published by the Slovenian Institute for Standardization (SIST). Its full title is "Network Aspects (NA); Accessibility for 64 kbit/s circuit switched international end-to-end ISDN traffic relations". This standard covers: This standard will specify the accessability of international end-to- end circuit switched 64 kbit/s traffic relations between T-reference points. The standard will not cover blocking at the user network interface nor catastrophic situations e.g. earthquakes, Floods etc.
This standard will specify the accessability of international end-to- end circuit switched 64 kbit/s traffic relations between T-reference points. The standard will not cover blocking at the user network interface nor catastrophic situations e.g. earthquakes, Floods etc.
SIST ETS 300 251 E1:2003 is classified under the following ICS (International Classification for Standards) categories: 33.040.40 - Data communication networks; 33.080 - Integrated Services Digital Network (ISDN). The ICS classification helps identify the subject area and facilitates finding related standards.
SIST ETS 300 251 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
Omrežni vidiki (NA) – Dostopnost mednarodnih vodovno komutiranih prometnih
povezav konec-konec za hitrosti 64 kbit/s v ISDN
Network Aspects (NA); Accessibility for 64 kbit/s circuit switched international end-to-end
ISDN traffic relations
Ta slovenski standard je istoveten z: ETS 300 251 Edition 1
ICS:
33.040.40 Podatkovna komunikacijska Data communication
omrežja networks
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 300 251
TELECOMMUNICATION August 1993
STANDARD
Source: ETSI TC-NA Reference: DE/NA-042106
ICS: 33.080
ISDN, access
Key words:
Network Aspects (NA);
Accessibility for 64 kbit/s circuit switched
international end-to-end ISDN traffic relations
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 1993. All rights reserved.
New presentation - see History box
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ETS 300 251: August 1993
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 300 251: August 1993
Contents
Foreword.5
1 Scope .7
2 Normative references .7
3 Definitions. 7
4 Symbols and abbreviations.8
5 Explicit definition for a measure for accessibility performance .8
5.1 Introduction.8
5.2 Principles and definitions.8
6 Requirements.9
7 Success criteria for connection attempts. 10
8 Evaluation of the NP measure for accessibility . 11
History. 13
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ETS 300 251: August 1993
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ETS 300 251: August 1993
Foreword
This European Telecommunication Standard (ETS) has been prepared by the Network Aspects (NA)
Technical Committee of the European Telecommunications Standards Institute (ETSI).
This ETS specifies the accessibility of international end-to-end circuit-switched 64 kbit/s Integrated
Services Digital Network (ISDN) traffic relations between T reference points.
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ETS 300 251: August 1993
Blank page
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ETS 300 251: August 1993
1 Scope
This European Telecommunication Standard (ETS) specifies the accessibility of international end-to-end
circuit-switched 64 kbit/s Integrated Services Digital Network (ISDN) traffic relations between T reference
points.
This ETS does not cover blocking at the user-network interface nor catastrophic situations, e.g. earth
quakes, floods, etc.
NOTE: A corresponding compliance ETS is planned for September 1994. Until the document is
available, this ETS may be used for design purposes.
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] Supplement No. 6 to CCITT E series Recommendations: "Terms and definitions
of Quality of Service, Network Performance, Dependability and Trafficability
studies".
[2] ETR 044: "Network Aspects (NA); Reference events for network performance
parameters in an ISDN".
[3] DE/NA-042104: "Network performance objectives for circuit-switched connection
processing delays in an ISDN".
[4] ETS 300 297: "Integrated Services Digital Network (ISDN); Access Digital
Section for ISDN basic rate".
[5] DI/NA-042117: "Network Aspects (NA); Accessibility for 64 kbit/s
circuit-switched international end-to-end ISDN traffic relations Conformance test
specification".
3 Definitions
For the purpose of this ETS, the following definitions apply:
Accessibility performance: the ability of a network to provide a connection within a specified delay when
a correct request is received from the user at the T interface.
NOTE: The request includes activation of layer 1.
Accessibility: a measure for accessibility performance. The explicit definition of the measure is given in
Clause 5 of this ETS.
Measure: a function or quantity used to describe a random variable or a random process (definition
number 3011 in Supplement No. 6 to CCITT E series Recommendations [1]).
Short Term Accessibility (STA): the explicit definition of the STA is given in Clause 5 of this ETS.
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ETS 300 251: August 1993
4 Symbols and abbreviations
For the purpose of this ETS, the following symbols and abbreviations are used:
MPT1 Measurement Point 1
NP Network Performance
STA Short Term Accessibility
T Time interval over which the random variable STA is defined
a
T interface at reference point T
SABME Set Asynchronous Balanced Mode Extended
UA Unnumbered Acknowledgement
5 Explicit definition for a measure for accessibility performance
5.1 Introduction
A Network Performance (NP) measure for accessibility performance should be as simple and easy to
evaluate as possible. On the other hand, as the quality of service measure for accessibility performance
depends mainly on the corresponding NP measure of the used network, a NP measure for accessibility
performance has to characterise, as accurately as possible, the aspects which are important for the user.
These requirements are conflicting and there
...