SIST ETS 300 345 E1:2003

• Abstract:

  General aspects of the interworking between public and private ISDNs

• 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 300 345 ed.1 (1995-01) - Integrated Services Digital Network (ISDN); Interworking between public ISDNs and private ISDNs for the provision of telecommunication services; General aspects

SIST ETS 300 345 E1:2003 is the SIST adoption of ETS 300 345 Edition 1 from the European Telecommunications Standards Institute (ETSI). It sets out the general aspects of interworking between public ISDNs and private ISDNs for telecommunication services. The standard is written for people who prepare, implement, or assess ISDN service specifications where traffic or signalling crosses between the public and private network domains.

What does SIST ETS 300 345 E1:2003 specify?

SIST ETS 300 345 E1:2003 specifies the general requirements that public ISDN service standards should follow when those services must interwork with private ISDNs. It explains where the public network, the private network, and the service user meet, and how service information should move between them.

The document is organized into clauses on scope, normative references, definitions, symbols and abbreviations, specification boundaries, service provision, public/private ISDN configurations, and general requirements. Annex A is an informative bibliography.

The scope focuses on service interworking between public ISDNs and private ISDNs. It excludes regulatory requirements, charging principles, standards or parts that describe private ISDN requirements, other uses of accesses such as private networking over leased lines via semi-permanent connections, and virtual private network configurations.

What are the key requirements of SIST ETS 300 345 E1:2003?

SIST ETS 300 345 E1:2003 is mainly a coordination document for service standards. It tells standards writers how to describe interworking at the right reference point, how to classify service provision, and how to handle numbering, access, congestion, and protocols in public/private ISDN cases.

Specification boundaries and conformance

Clause 5 says that standards for public ISDN services should describe user-facing service behavior at the coincident S and T reference points, while interworking with private ISDNs is described at the T reference point. For general procedures in public ISDNs, the same clause says to use the T reference point, and where appropriate the coincident S and T reference points.

This matters because the same service can be specified differently depending on whether the user is directly attached to the public ISDN or reaches it through a private ISDN. The document also says conformance is checked by inspection, and no test method is provided.

Service provision models

Clause 6 groups supplementary service support into three provision categories: local provision, double provision, and cooperative provision. Local provision means only one ISDN’s Service Provider Function (SPF) is involved, double provision means each ISDN provides its own local instance, and cooperative provision means the public and private SPFs work together across the T reference point.

In practice, this classification tells the service designer how much of the service logic sits in each network. It also explains why a public ISDN standard may need different procedures for the same service depending on how the private ISDN participates.

Stage 1, stage 2, and stage 3 relationships

Clause 6 links the interworking model to stage 1, stage 2, and stage 3 service standards. For stage 1, local provision is described in the procedures clause, double provision is treated as two local provisions, and cooperative provision combines procedures with additional interworking requirements.

For stage 2, the document uses Functional Entity (FE) scenarios to show where the service logic may sit in the public ISDN, the private ISDN, or the terminal. For stage 3, it says that local provision at the coincident S and T reference points should also apply at the T reference point, while cooperative provision needs procedures specifically for interworking between the two networks.

Public/private ISDN configurations

Clause 7 allows more than one T reference point in practice. It lists several network arrangements, including one private ISDN connected to more than one public ISDN, one public ISDN connected to more than one private ISDN exchange, and other combinations of public and private exchanges.

This matters for real deployments because a private network may reach the public network through several accesses or several providers. Clause 7 also says these interconnections can use basic access, primary rate access, or a combination, and selection can be done by a single number or by a number range.

Numbering, access, congestion, and protocols

Clause 8 says that at the T reference point only ISDN numbers, or parts of them, should appear, except for some supplementary service cases. That applies both to selection and identification, so numbering plans and dialling arrangements need to stay aligned with ISDN addressing practice.

Clause 8.2 says service interworking should be described in general form so it can work over any access type between the public and private ISDNs. Clause 8.3 adds that when congestion is encountered at an access from the public ISDN to the private ISDN, the call request should be rejected and the user should get a congestion indication.

Clause 8.4 says interworking for ETSI standardised services should use ETSI standardised functional protocols only. Clause 8.5 places management outside the scope of the standard.

What terms does SIST ETS 300 345 E1:2003 define?

• public ISDN - An ISDN that provides services to the general public.
• private ISDN - An ISDN that provides services only to a specific set of users.
• S reference point - The point where terminals are indirectly connected to the public ISDN through a private ISDN.
• T reference point - The service interworking point where a public ISDN and a private ISDN meet.
• coincident S and T reference points - The case where terminals are directly attached to the public ISDN, shown as S/T.
• Service Provider Function (SPF) - The function in an ISDN that provides a bearer service or teleservice, excluding terminal functionality.
• Functional Entity (FE) - The service-building entity used in stage 2 scenarios and figures.
• ISDN number - A number that follows the ISDN numbering plan and structure of CCITT Recommendation E.164.

Who uses SIST ETS 300 345 E1:2003?

SIST ETS 300 345 E1:2003 is used by standards writers, network planners, service providers, and equipment vendors working with ISDN interworking. It is especially relevant when a service must work both in public ISDNs and in private ISDNs without changing the user-facing service description.

It also helps organizations that define bearer services, teleservices, and supplementary services for public ISDNs. In practice, these readers use it to decide where service logic belongs, what reference point to specify, and how to align public and private network behavior.

What changed in SIST ETS 300 345 E1:2003 from the previous edition?

SIST ETS 300 345 E1:2003 corresponds to ETS 300 345 Edition 1. The document history identifies the first edition as January 1995 and notes a later PDF conversion in January 1996.

Which standards are used with SIST ETS 300 345 E1:2003?

The normative references provide the background definitions and service model used by this standard:

• CCITT Recommendation I.130 - defines the stage 1, stage 2, and stage 3 service characterisation method.
• CCITT Recommendation I.411 - defines ISDN user-network interface structures and access capabilities, including the S reference point.
• CCITT Recommendation E.164 - provides the ISDN numbering plan.
• CCITT Recommendation I.112 - supplies core ISDN vocabulary, including service, bearer service, teleservice, and ISDN.
• CCITT Recommendation I.210 - sets out principles for ISDN telecommunications services and defines supplementary service.
• CCITT Recommendation Q.65 - gives the stage 2 characterisation method for services supported by an ISDN.

The standard also points readers to ETR 076 for more information on service standardization and interworking relationships.

What does the SIST ETS 300 345 E1:2003 document contain?

The document contains the service model for public/private ISDN interworking, supported by reference-point definitions and network scenarios. It includes figures that show how SPFs and FEs are placed for local, double, and cooperative provision, and how different public/private ISDN configurations relate to the T reference point.

It also contains the general numbering, access, congestion, and protocol rules that later service standards are expected to take into account. For implementation teams, it is mainly a design and specification guide rather than a test procedure, because it directs how service standards should be written and says conformance is checked by inspection.

SLOVENSKI STANDARD
01-december-2003
Digitalno omrežje z integriranimi storitvami (ISDN) – Medsebojno delovanje javnih
in zasebnih ISDN zaradi zagotavljanja telekomunikacijskih storitev – Splošni vidiki
Integrated Services Digital Network (ISDN); Interworking between public ISDNs and
private ISDNs for the provision of telecommunication services; General aspects
Ta slovenski standard je istoveten z: ETS 300 345 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 300 345
TELECOMMUNICATION January 1995
STANDARD
Source: ETSI TC-NA Reference: DE/NA-012243
ICS: 33.080
ISDN, interworking, services
Key words:
Integrated Services Digital Network (ISDN);
Interworking between public ISDNs and private ISDNs
for the provision of telecommunication services;
General aspects
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 - [e-mail]
X.400: Internet:
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 1995. All rights reserved.
New presentation - see History box

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ETS 300 345: January 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 300 345: January 1995
Contents
Foreword .5
Introduction.5
1 Scope .7
2 Normative references.7
3 Definitions.8
4 Symbols and abbreviations .9
5 Specification boundaries .9
6 Service provision .10
6.1 Relationship to stage 1 standards for public ISDNs .11
6.2 Relationship to stage 2 standards for public ISDNs .11
6.2.1 Local provision .12
6.2.2 Double provision.13
6.2.3 Cooperative provision.13
6.3 Relationship to stage 3 standards for public ISDNs .14
6.3.1 "Local" provision.14
6.3.2 "Double" provision .14
6.3.3 "Cooperative" provision .15
6.4 Relationship to standards for general procedures in public ISDNs .15
7 Public/private ISDN configurations.15
8 General requirements for interworking between public ISDNs and private ISDNs .16
8.1 Numbering .16
8.2 Accesses between public ISDNs and private ISDNs.16
8.3 Access congestion.17
8.4 Protocol requirements.17
8.5 Management.17
Annex A (informative): Bibliography.18
History.19

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ETS 300 345: January 1995
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ETS 300 345: January 1995
Foreword
This European Telecommunication Standard (ETS) has been produced by the Network Aspects (NA)
Technical Committee of the European Telecommunications Standards Institute (ETSI).
This ETS details the general aspects of interworking between public Integrated Services Digital Networks
(ISDNs) and private ISDNs for the provision of telecommunication services.
Transposition dates
Date of latest announcement of this ETS (doa): 30 April 1995
Date of latest publication of new National Standard 31 October 1995
or endorsement of this ETS (dop/e):
Date of withdrawal of any conflicting National Standard (dow): 31 October 1995
Introduction
Work on this standard began as a result of an agreement between rapporteurs from ETSI Sub Technical
Committee (STC) NA 1 and rapporteurs from Technical Committee TC 32-TG6 of the European
Computer Manufacturers' Association (ECMA). That agreement recognised the need for a single text
which documents items that were common to supplementary services in order to avoid repetition in each
of the service descriptions.
Subsequently the text has been refined by NA 1 in consultation with Signalling, Protocols and Switching
(SPS) Technical Committee of ETSI.
This standard includes normative information on the interworking between public ISDNs and private
ISDNs. It indicates reference points where this has to occur.
The standard has been developed as a reference document for the standardisation of telecommunication
services when these services are provided in either or both ISDNs and thus service interworking becomes
necessary for calls involving both public ISDNs and private ISDNs.
In developing this standard it has been assumed that as a general rule, the same terminals can be
connected to the public ISDN or to the private ISDN.
This standard does not cover virtual private network configurations.

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ETS 300 345: January 1995
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ETS 300 345: January 1995
1 Scope
This standard describes general requirements on standards for services with respect to interworking
between public Integrated Services Digital Networks (ISDNs) and private ISDNs. This standard describes
the different mechanisms whereby services implemented by public ISDNs can be provided to users
attached to private ISDNs.
Service specific information on the interworking between public ISDNs and private ISDNs is given in the
various standards for the individual bearer services, teleservices and supplementary services.
In addition, this standard identifies the need for general procedures in the public ISDN required to support
the transport of information given to other users as a result of the operation of services in the private
ISDN.
Consideration of regulatory requirements placed on public ISDNs and/or private ISDNs is outside the
scope of this standard.
For the purpose of this standard, only the accesses used for interworking between public ISDNs and
private ISDNs are considered. The use of accesses for any other purpose e.g. for private networking over
leased-lines via semi-permanent connections, is outside the scope of this standard.
Charging principles are outside the scope of this standard.
This standard is applicable to the stage one standards describing individual services for public ISDNs and
to standards describing general public ISDN procedures for ISDN services. This standard is also
applicable to the stage two and stage three standards for the individual services for public ISDNs
described in the stage one standards. The terms "stage one", "stage two" and "stage three" are defined in
CCITT Recommendation I.130 [1].
Standards, or parts of standards, describing requirements on private ISDNs are outside the scope of this
standard.
Furthermore, conformance to this standard is met by equipment conforming to the stage three standards
(which in turn conform to this standard and the relevant stage 1 and stage 2 standards) with the field of
application appropriate to the equipment being implemented. Conformance to this standard by the stage
1, stage 2 and stage 3 standards can be checked by inspection. Therefore, no method of testing is
provided for this standard.
2 Normative references
This standard 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 standard only when incorporated in it by amendment or revision. For undated references the
latest edition of the publication referred to applies.
[1] CCITT Recommendation I.130 (1988): "Method for the characterisation of
telecommunication services supported by an ISDN and network capabilities of
an ISDN".
[2] CCITT Recommendation I.411 (1988): "ISDN user-network interfaces - Interface
structures and access capabilities".
[3] CCITT Recommendation E.164 (1991): "Numbering plan for the ISDN era".
[4] CCITT Recommendation I.112 (1988): "Vocabulary of terms for ISDNs".
[5] CCITT Recommendation I.210 (1988): "Principles of telecommunications
services supported by an ISDN and the means to describe them".
[6] CCITT Recommendation Q.65 (1988): "Stage 2 of the method for the
characterization of services supported by an ISDN".

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ETS 300 345: January 1995
3 Definitions
For the purposes of this standard, the following definitions apply:
public ISDN: An ISDN which provides services to the general public.
private ISDN: An ISDN which provides services to a specific set of users only.
S reference point: The reference point at which terminals are indirectly connected with the public ISDN,
i.e. are attached to a private ISDN and communicate with the public ISDN via a private ISDN In figures,
this reference point is denoted by S. See CCITT Recommendation I.411 [2].
T reference point: The reference point at which a private and a public ISDN are interconnected and have
to interwork for the provision of telecommunication services. In figures, this reference point is denoted by
T.
For the purpose of this standard the term "T reference point" shall always denote the service interworking
point between a public ISDN and a private ISDN, i.e. other interworking situations between the public
ISDN and other equipment, as conceivable according to CCITT Recommendation I.411 [2], are excluded.
coincident S and T reference points: These reference points coincide when terminals are directly
attached to the public ISDN. In figures, this is denoted by S/T.
NOTE: The notation S/T should not be interpreted as "either S or T".
service provider function: Within a public ISDN or private ISDN, the functionality which provides a
bearer service, or a teleservice, excluding any possible terminal functionality for that service.
terminal equipment: See CCITT Recommendation I.411 [2], § 3.4.3.
service, telecommunication service: See CCITT Recommendation I.112 [4], § 2.2, definition 201.
bearer service: See CCITT Recommendation I.112 [4], § 2.2, definition 202.
teleservice: See CCITT Recommendation I.112 [4], § 2.2, definition 203.
supplementary service: See CCITT Recommendation I.210 [5], § 2.4.
Integrated Services Digital Network (ISDN): See CCITT Recommendation I.112 [4], § 2.3,
definition 308.
served user: The user to whom a bearer service, teleservice or supplementary service is provided.
functional entity: See CCITT Recommendation Q.65 [6], § 2.1.1.
ISDN number: A number conforming to the numbering plan and structure specified in CCITT
Recommendation E.164 [3].
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ETS 300 345: January 1995
4 Symbols and abbreviations
For the purposes of this standard, the following abbreviations apply:
FE Functional Entity
ISDN Integrated Services Digital Network
SPF Service Provider Function
TE Terminal Equipment
5 Specification boundaries
Standards for specific public ISDN services shall be specified in relation to users whose equipment is
connected to the public ISDN by an interface at the coincident S and T reference points. The interworking
aspects of these services with private ISDNs shall be specified in relation to T reference points.
Standards for general procedures in public ISDNs specifying interworking aspects with private ISDN
services shall be specified in relation to T reference points and, where appropriate, to coincident S and T
reference points. The standards for these general procedures shall define how the information is relayed
to the user in the other ISDN.
An overview of specification boundaries is given in figure 1.
Public ISDN Private ISDN
TE TE
S/T S
T
S/T
S
TE
TE
NOTE: For simplicity reasons, this figure shows only the connection of one private ISDN with
one public ISDN. Other configurations can also occur e.g. the configuration where one
private ISDN is connected to another private ISDN via a public ISDN.
Figure 1: Specification boundaries

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ETS 300 345: January 1995
6 Service provision
This standard does not require that corresponding services in both types of ISDN are absolutely identical.
However, interworking will be more complicated when there are significant differences In order to ease
problems in interworking between services in the public ISDN and in the private ISDN, where no standard
for a particular service exists in the public ISDN, but a corresponding standard exists for the service in the
private ISDN, the private ISDN standard shall be used as the basis (and vice versa). More information can
be found in annex D of ETR 076.
In order to use a service, the served user has access to a Service Provider Function (SPF). For the
purposes of this standard, teleservices are viewed as being supported by one SPF for each of the private
ISDNs and one SPF for each of the public ISDNs involved. A standard for a teleservice in a public ISDN
shall describe bearer services and bearer capabilities required for the support of that teleservice when
interworking with private ISDNs.
Supplementary services can be supported by several cooperating SPFs in an ISDN. For the purposes of
this standard, supplementary services are viewed as being supported by one SPF for each of the private
ISDNs and one SPF for each of the public ISDNs involved. A standard for a supplementary service in a
public ISDN shall describe the requirements for the support of that supplementary service when
interworking with private ISDNs.
Where calls pass through a public ISDN and a private ISDN, the SPFs of both ISDNs will be involved (see
figure 2). For supplementary service functionality, however, one of the SPFs may be transparent.
The degree of involvement of each SPF varies, depending on the bearer service, teleservice or
supplementary service concerned. For bearer services and teleservices, ther
...