ISO/IEC 15773:1998

Information technology — Telecommunications and information exchange between systems — Broadband Private Integrated Services Network — Inter-exchange signalling protocol — Transit counter additional network feature

This International Standard specifies the signaling protocol for the support of the Transit Counter additional network feature (ANF-TC) at the Q reference point between Private Integrated Services Network Exchanges (PINXs) connected together within a Broadband Private Integrated Services Network (B-PISN). ANF-TC is a feature that limits the number of Transit PINXs that a call/connection setup request may be routed through e.g., to protect the network against indefinite looping. The Q reference point is defined in ISO/IEC 11579-1. Service specifications are produced in three stages and according to the method specified in CCITT Rec. I.130. This International Standard contains the stage 3 specification for the Q reference point and satisfies the requirements identified by the stage 1 and stage 2 specifications in ISO/IEC 15055. The signaling protocol for ANF-TC operates in association with the signaling protocols for basic call/connection control (as specified in ISO/IEC 13247) and call independent (connection oriented) signaling connections (as specified in ECMA-254). This International Standard is applicable to PINXs that can interconnect to form a PISN.

Technologies de l'information — Télécommunications et échange d'information entre systèmes — Réseau privé à large bande à intégration de services — Protocole de signalisation d'échange — Caractéristique de réseau additionnelle de compteur de transit

General Information

• Status: Published
• Publication Date: 15-Jul-1998
• ICS: 33.040.35 - Telephone networks
• Technical Committee: ISO/IEC JTC 1/SC 6 - Telecommunications and information exchange between systems
• Drafting Committee: ISO/IEC JTC 1/SC 6 - Telecommunications and information exchange between systems
• Current Stage: 9060 - Close of review
• Start Date: 02-Dec-2025

Standards Content (Sample)

INTERNATIONAL ISO/IEC
STANDARD 15773
First edition
1998-07-15
Information technology —
Telecommunications and information
exchange between systems — Broadband
Private Integrated Services Network —
Inter-exchange signalling protocol —
Transit counter additional network feature
Technologies de l'information — Télécommunications et échange
d’information entre systèmes — Réseau privé à large bande à intégration
de services — Protocole de signalisation d’échange — Caractéristique de
réseau additionnelle de compteur de transit
Reference number
B C
ISO/IEC 15773:1998(E)

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ISO/IEC 15773:1998(E)
Contents
Foreword iii
Introduction iv
Scope
1 1
Conformance
2 1
Normative references
3 1
Definitions
4 2
External definitions
4.1 2
List of acronyms
5 2
Signalling protocol for the support of ANF-TC
6 2
ANF-TC description
6.1 2
ANF-TC operational requirements
6.2 3
Requirements on the Originating PINX
6.2.1 3
Requirements on the Terminating PINX
6.2.2 3
Requirements on a Transit PINX
6.2.3 3
ANF-TC coding requirements
6.3 3
Transit counter information element
6.3.1 3
Messages
6.3.2 4
ANF-TC signalling procedures
6.4 4
Actions at the Originating PINX
6.4.1 4
Actions at the Terminating PINX
6.4.2 4
Actions at a Transit PINX
6.4.3 4
At an Incoming Gateway PINX
6.4.4 4
At an Outgoing Gateway PINX
6.4.5 4
- Protocol Implementation Conformance Statement (PICS) proforma
Annex A 5
- Guidelines for interworking with ATM Forum PNNI 1.0
Annex B 9
©  ISO/IEC 1998
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or
utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm,
without permission in writing from the publisher.
ISO/IEC Copyright Office • Case postale 56 • CH-1211 Genève 20 • Switzerland
Printed in Switzerland
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© ISO/IEC ISO/IEC 15773:1998(E)
Foreword
ISO (the International Organization for Standardization) and IEC (the International Electrotechnical Commission) form the
specialized system for worldwide standardization. National bodies that are members of ISO or IEC participate in the
development of International Standards through technical committees established by the respective organization to deal with
particular fields of technical activity. ISO and IEC technical committees collaborate in fields of mutual interest. Other
international organizations, governmental and non-governmental, in liaison with ISO and IEC, also take part in the work.
In the field of information technology, ISO and IEC have established a joint technical committee, ISO/IEC JTC 1. Draft
International Standards adopted by the joint technical committee are circulated to national bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the national bodies casting a vote.
International Standard ISO/IEC 15773 was prepared by ECMA (as ECMA-252) and was adopted, under a special “fast-track
procedure”, by Joint Technical Committee ISO/IEC JTC 1, Information technology, in parallel with its approval by national
bodies of ISO and IEC.
Annex A forms an integral part of this International Standard. Annex B is for information only.
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ISO/IEC 15773:1998(E) © ISO/IEC
Introduction
This International Standard is one of a series of standards defining services and signalling protocols applicable to Broadband
Private Integrated Services Networks. The series uses the B-ISDN concepts as developed by ITU-T and is also within the
framework of standards for open systems interconnection as defined by ISO.
This International Standard specifies the signalling protocol for use at the Q reference point in support of the Transit Counter
additional network feature.
This International Standard is based upon the practical experience of ECMA member companies and the results of their active
and continuous participation in the work of ISO/IEC JTC 1, ITU-T, ETSI and other international and national standardization
bodies. It represents a pragmatic and widely based consensus.
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INTERNATIONAL STANDARD  ©ISO/IEC ISO/IEC 15773:1998(E)
Information technology — Telecommunications and information exchange between
systems — Broadband Private Integrated Services Network — Inter-exchange
signalling protocol — Transit counter additional network feature
1 Scope
This International Standard specifies the signalling protocol for the support of the Transit Counter additional network feature
(ANF-TC) at the Q reference point between Private Integrated Services Network Exchanges (PINXs) connected together
within a Broadband Private Integrated Services Network (B-PISN).
ANF-TC is a feature that limits the number of Transit PINXs that a call/connection setup request may be routed through e.g.,
to protect the network against indefinite looping.
The Q reference point is defined in ISO/IEC 11579-1.
Service specifications are produced in three stages and according to the method specified in CCITT Rec. I.130. This
International Standard contains the stage 3 specification for the Q reference point and satisfies the requirements identified by
the stage 1 and stage 2 specifications in ISO/IEC 15055.
The signalling protocol for ANF-TC operates in association with the signalling protocols for basic call/connection control (as
specified in ISO/IEC 13247) and call independent (connection oriented) signalling connections (as specified in ECMA-254).
This International Standard is applicable to PINXs that can interconnect to form a PISN.
2 Conformance
In order to conform to this International Standard, a PINX shall satisfy the requirements identified in the Protocol
Implementation Conformance Statement (PICS) proforma in annex A.
3 Normative references
The following standards contain provisions which, through reference in this text, constitute provisions of this International
Standard. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to
agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent
editions of the standards indicated below. Members of IEC and ISO maintain registers of currently valid International
Standards.
ISO/IEC 11579-1:1994, Information technology - Telecommunications and information exchange between systems - Private
Integrated Services Network - Part 1: Reference configuration for PISN Exchanges (PINX).
ISO/IEC 13247:1997, Information technology - Telecommunications and information exchange between systems -
Broadband Private Integrated Services Network - Inter-exchange signalling protocol - Basic
call/connection control.
ISO/IEC 15055:1997, Information technology - Telecommunications and information exchange between systems - Private
Integrated Services Network - Specification, functional model and information flows - Transit
counter additional network feature.
ECMA-254:1996, Broadband Private Integrated Services Network (B-PISN) - Inter-Exchange Signalling Protocol -
Generic Functional Protocol.
CCITT Rec. I.112:1988, Vocabulary of terms for ISDNs.
CCITT Rec. I.130:1988, Method for the characterization of telecommunication services supported by an ISDN and network
capabilities of an ISDN.
CCITT Rec. I.210:1988, Principles of telecommunication services supported by an ISDN and the means to describe them.
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ISO/IEC 15773:1998(E)     ISO/IEC
4 Definitions
For the purposes of this International Standard, the following definitions apply.
4.1 External definitions
This International Standard uses the following terms defined in other documents:
- Basic Service (CCITT Rec. I.210)
- Call, Basic Call (ECMA-254)
- Call Independent Signalling Connection (ECMA-254)
- Incoming Gateway PINX (ISO/IEC 13247)
- Incoming Side (ISO/IEC 13247)
- Inter-PTNX Link (ISO/IEC 13247)
- Originating PINX (ISO/IEC 13247)
- Outgoing Gateway PINX (ISO/IEC 13247)
- Outgoing Side (ISO/IEC 13247)
- Preceding PINX (ISO/IEC 13247)
- Private Integrated Services Network (PISN) (ISO/IEC 11579-1)
- Private Integrated Services Network Exchange (PINX) (ISO/IEC 11579-1)
- Signalling (CCITT Rec. I.112)
- Subsequent PINX (ISO/IEC 13247)
- Supplementary Service (CCITT Rec. I.210)
- Terminating PINX (ISO/IEC 13247)
- Transit PINX (ISO/IEC 13247)
5 List of acronyms
ANF Additional Network Feature
ANF-TC Transit Counter Additional Network Feature
B-ISDN Broadband Integrated Services Digital Network
B-PISN Broadband Private Integrated Services Network
PICS Protocol Implementation Conformance Statement
PINX Private Integrated Services Network Exchange
PISN Private Integrated Services Network
6 Signalling protocol for the support of ANF-TC
6.1 ANF-TC description
ANF-TC is invoked when it is desired to limit the number of Transit PINXs that a call/connection setup request may be routed
through.
This additional network feature is applicable to the broadband connection oriented bearer service.
ANF-TC may be used in conjunction with either a Basic call setup request or a setup request for a call independent
(connection oriented) signalling connection.
Use of ANF-TC is a network option. The criteria for determining:
− when ANF-TC should be invoked;
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ISO/IEC  ISO/IEC 15773:1998(E)
− the number of PINXs through which a call may be routed; and,
− the means by which the feature is activated or deactivated
are network dependent and outside the scope of this International Standard.
6.2 ANF-TC operational requirements
6.2.1 Requirements on the Originating PINX
Call/connection establishment procedures for the outgoing side of an inter-PINX link and call/connection release procedures,
as specified in ISO/IEC 13247, shall apply.
If the PINX supports connection-oriented APDU transport, then the generic procedures for the call independent control
(connection oriented) of supplementary services, as specified in ECMA-254 for an Originating PINX, shall apply.
6.2.2 Requirements on the Terminating PINX
Call/connection establishment procedures for the incoming side of an inter-PINX link and call/connection release procedures,
as specified in ISO/IEC 13247, shall apply.
If the PINX supports connection-oriented APDU transport, then the generic procedures for the call independent control
(connection oriented) of supplementary services, as specified in ECMA-254 for a Terminating PINX, shall apply.
6.2.3 Requirements on a Transit PINX
Basic call procedures for call/connection establishment and call/connection clearing at a Transit PINX, as specified in ISO/IEC
13247, shall apply.
If the PINX supports connection-oriented APDU transport, then the generic procedures for the call independent control
(connection oriented) of supplementary services, as specified in ECMA-254 for a Transit PINX, shall apply.
6.3 ANF-TC coding requirements
6.3.1 Transit counter information element
ANF-TC shall be encoded as a discrete information element (called Transit counter) within codeset 4 (ISO codeset), according
to the rules for the general format and coding of variable length information elements defined in 8.5.1 of ISO/IEC 13247.
The Transit counter information element shall be a variable length category 1 (see 12.1.9.2 of ISO/IEC 13247) information
element with the format shown in figure 1 and coded as shown in table 1.
87 654 321 Octet
Transit counter
0 0 110 001 1
Information element identifier
1 Coding IE compatibility instr. indicator 2
ext standard Flag Pass IE Action Ind.
along
Length of transit counter contents 3
4
1 0 0 Transit count 5
ext Reserved (binary value)
Figure 1 - Transit counter information element
Table 1 - Transit counter information element
Transit count (octet 3)
A binary value (in the range 0 - 31) that indicates the number of
Transit PINXs through which the SETUP request has already
passed
...