ISO/IEC 13874:1999

Information technology - Telecommunications and information exchange between systems - Private Integrated Services Network - Inter-exchange signalling protocol - Path replacement additional network feature

Technologies de l'information — Télécommunications et échange d'information entre systèmes — Réseau privé à intégration de services — Protocole de signalisation d'échange — Caractéristique de réseau additionnelle de remplacement de chemin

General Information

• Status: Withdrawn
• Publication Date: 20-Jan-1999
• Withdrawal Date: 20-Jan-1999
• 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: 9599 - Withdrawal of International Standard
• Start Date: 21-Mar-2003
• Completion Date: 30-Oct-2025

Relations

• Revises: ISO/IEC 13874:1995/Cor 1:1996 - Information technology - Telecommunications and information exchange between systems - Private Integrated Services Network - Inter-exchange signalling protocol - Path replacement additional network feature - Technical Corrigendum 1
• Effective Date: 15-Apr-2008
• Revised: ISO/IEC 13874:2003 - Information technology - Telecommunications and information exchange between systems - Private Integrated Services Network - Inter-exchange signalling protocol - Path Replacement additional network feature
• Effective Date: 15-Apr-2008
• Revises: ISO/IEC 13874:1995 - Information technology - Telecommunications and information exchange between systems - Private Integrated Services Network - Inter-exchange signalling protocol - Path replacement additional network feature
• Effective Date: 15-Apr-2008

Standards Content (Sample)

INTERNATIONAL ISO/IEC
STANDARD 13874
Second edition
1999-01-15
Information technology —
Telecommunications and information
exchange between systems — Private
Integrated Services Network —
Inter-exchange signalling protocol — Path
replacement additional network feature
Technologies de l'information — Télécommunications et échange
d'information entre systèmes — Réseau privé à intégration de services —
Protocole de signalisation d'échange — Caractéristique de réseau
additionnelle de remplacement de chemin
Reference number
B C
Contents
Foreword iv
Introduction v
1 Scope 1
2 Conformance 1
3 Normative references 1
4 Definitions 2
4.1 External definitions 2
4.2 Other definitions 3
4.2.1 Branching PINX 3
4.2.2 Cooperating PINX 3
4.2.3 End PINX 3
4.2.4 Preceding PINX 3
4.2.5 Replaced connection 3
4.2.6 Requesting PINX 3
4.2.7 Retained connection 3
4.2.8 Subsequent PINX 3
4.2.9 Inviting PINX 3
5 List of acronyms 3
6 Signalling protocol for the support of ANF-PR 3
6.1 ANF-PR description 3
6.2 ANF-PR operational requirements 4
6.2.1 Requirements on the Cooperating PINX 4
6.2.2 Requirements on the Requesting PINX 4
6.2.3 Requirements on a Transit PINX 4
6.2.4 Requirements on the Inviting PINX 5
6.3 ANF-PR coding requirements 5
6.3.1 Operations 5
6.3.2 Information elements 9
6.3.3 Messages 10
6.4 ANF-PR state definitions 10
6.4.1 States at the Requesting PINX 10
6.4.2 States at the Cooperating PINX 10
6.4.3 States at a Transit PINX on the retained path, including the branching PINX 10
6.4.4 States at the Inviting PINX 11
6.5 ANF-PR signalling procedures 11
©  ISO/IEC 1999
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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6.5.1 Actions at the Requesting PINX 11
6.5.2 Actions at the Cooperating PINX 12
6.5.3 Actions at a Cooperating/Requesting PINX in the case of a trombone connection 13
6.5.4 Actions at a Transit PINX 13
6.5.5 Actions at Inviting PINX 13
6.6 ANF-PR optional signalling procedures for retention of part of the old connection 14
6.6.1 Actions at the Requesting PINX 14
6.6.2 Actions at the Cooperating PINX 14
6.6.3 Actions at a Transit PINX on the retained connection 14
6.6.4 Actions at a Transit PINX on the new connection or replaced connection 16
6.6.5 Actions at Inviting PINX on the retained connection 16
6.7 ANF-PR impact of interworking with public ISDNs 16
6.8 ANF-PR impact of interworking with non-ISDNs 16
6.9 Protocol interactions between ANF-PR and other supplementary services and ANFs 16
6.9.1 Interaction with Calling Name Identification Presentation (SS-CNIP) 16
6.9.2 Interaction with Connected Name Identification Presentation (SS-CONP) 16
6.9.3 Interaction with Completion of Calls to Busy Subscriber (SS-CCBS) 16
6.9.4 Interaction with Completion of Calls on No Reply (SS-CCNR) 17
6.9.5 Interaction with Call Transfer (SS-CT) 17
6.9.6 Interaction with Call Forwarding Unconditional (SS-CFU) 18
6.9.7 Interaction with Call Forwarding Busy (SS-CFB) 18
6.9.8 Interaction with Call Forwarding No Reply (SS-CFNR) 18
6.9.9 Interaction with Call Deflection (SS-CD) 18
6.10 ANF-PR parameter values (timers) 18
6.10.1 Timer T1 18
6.10.2 Timer T2 18
6.10.3 Timer T3 18
6.10.4 Timer T4 18
Annexes
A - Protocol Implementation Conformance Statement (PICS) proforma 20
B - Imported ASN.1 definitions 27
C - Examples of message sequences 28
D - Specification and Description Language (SDL) representation of procedures 36
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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 13874 was prepared by ECMA (as ECMA-176) 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.
This second edition cancels and replaces the first edition (ISO/IEC 13874:1995), which has been technically revised.
Annex A forms an integral part of this International Standard. Annexes B, C and D are for information only.
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Introduction
This International Standard is one of a series of International Standards defining services and signalling protocols applicable to
Private Integrated Services Networks (PISNs). The series uses ISDN concepts as developed by ITU-T and conforms to the
framework of International Standards for Open Systems Interconnection as defined by ISO/IEC.
This International Standard specifies the signalling protocol for use at the Q reference point in support of the Path
Replacement additional network feature. The protocol defined in this International Standard forms part of the PSS1 protocol
(informally known as QSIG).
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 JTC1, 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 13874:1999(E)
Information technology — Telecommunications and information exchange between
systems — Private Integrated Services Network — Inter-exchange signalling
protocol — Path replacement additional network feature
1 Scope
This International Standard specifies the signalling protocol for the support of the Path Replacement additional network feature
(ANF-PR) at the Q reference point between Private Integrated Services Network Exchanges (PINXs) connected together within
a Private Integrated Services Network (PISN).
ANF-PR is a feature which applies to an established call, allowing that call's connection between PINXs to be replaced by a new
connection.
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 Recommendation 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 13863.
The signalling protocol for ANF-PR operates on top of the signalling protocol for basic circuit switched call control, as specified
in ISO/IEC 11572, and uses certain aspects of the generic procedures for the control of supplementary services specified in
ISO/IEC 11582.
This International Standard also specifies additional signalling protocol requirements for the support of interactions at the Q
reference point between ANF-PR and other supplementary services and ANFs.
This International Standard is applicable to PINXs which 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 11571:1994, Information technology - Telecommunications and information exchange between systems -
Numbering and sub-addressing in private integrated services networks.
ISO/IEC 11572:1997, Information technology - Telecommunications and information exchange between systems - Private
Integrated Services Network - Circuit mode bearer services - Inter-exchange signalling procedures
and protocol.
ISO/IEC 11574:1994, Information technology - Telecommunications and information exchange between systems - Private
Integrated Services Network - Circuit-mode 64 kbit/s bearer services - Service description, functional
capabilities and information flows.
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 11582:1995, Information technology - Telecommunications and information exchange between systems - Private
Integrated Services Network - Generic functional protocol for the support of supplementary services -
Inter-exchange signalling procedures and protocol.
ISO/IEC 13863:1998, Information technology - Telecommunications and information exchange between systems - Private
Integrated Services Network - Specification, functional model and information flows - Path
replacement additional network feature.
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ISO/IEC 13869:1995, Information technology - Telecommunications and information exchange between systems - Private
Integrated Services Network - Inter-exchange signalling protocol - Call transfer supplementary
service.
ISO/IEC 15056:1997, Information technology - Telecommunications and information exchange between systems - Private
Integrated Services Network - Inter-exchange signalling protocol - Transit counter additional network
feature.
ITU-T Rec. I.112:1993, 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.
ITU-T Rec. I.210:1993, Principles of telecommunication services supported by an ISDN and the means to describe them.
ITU-T Rec. Q.950:1993, Digital Subscriber Signalling System No. 1 (DSS 1) - Supplementary services protocols, structure and
general principles.
ITU-T Rec. Z.100:1993, Specification and description language.
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:
− ANF-PR user (ISO/IEC 13863)
− Application Protocol Data Unit (APDU) (ISO/IEC 11582)
− Basic Service (ITU-T Rec. I.210)
− Call, Basic Call (ISO/IEC 11582)
− Connection (ISO/IEC 13863)
− Incoming Gateway PINX (ISO/IEC 11572)
− Interpretation APDU (ISO/IEC 11582)
− Network Facility Extension (NFE) (ISO/IEC 11582)
− New Connection (ISO/IEC 13863)
− Old Connection (ISO/IEC 13863)
− Originating PINX (ISO/IEC 11572)
− Outgoing Gateway PINX (ISO/IEC 11572)
− Private Integrated Services Network (PISN) (ISO/IEC 11579-1)
Private Integrated Services Network Exchange (PINX) (ISO/IEC 11579-1)
−
− Signalling (ITU-T Rec. I.112)
− Supplementary Service (ITU-T Rec. I.210)
− Supplementary Services Control Entity (ISO/IEC 11582)
Terminating PINX (ISO/IEC 11572)
−
− Transit PINX (ISO/IEC 11572)
− Trombone Connection (ISO/IEC 13863)
− User (except in the context of ANF-PR user) (ISO/IEC 11574)
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4.2 Other definitions
4.2.1 Branching PINX : The Transit PINX at which the retained connection finishes and the new connection starts.
4.2.2 Cooperating PINX : The end PINX which initiates the establishment of the new connection towards other end PINX
involved in the call.
4.2.3 End PINX : Within the context of a call, a PINX which is not acting as a Transit PINX, i.e., an Originating PINX, a
Terminating PINX, an Incoming Gateway PINX or an Outgoing Gateway PINX.
4.2.4 Preceding PINX : The adjacent PINX in the direction of the Cooperating PINX, relative to a particular PINX involved in
the old connection.
Note 1 - This can be the Cooperating PINX itself or a Transit PINX.
4.2.5 Replaced connection : That part of the old connection which is not retained and is replaced by the new connection.
4.2.6 Requesting PINX : The end PINX which invokes ANF-PR and towards which the new connection is routed.
4.2.7 Retained connection : That part of the old connection which is retained and not replaced by the new connection.
4.2.8 Subsequent PINX : The adjacent PINX in the direction of the Requesting PINX, relative to a particular PINX involved in
the old connection.
Note 2 - This can be the Requesting PINX itself or a Transit PINX.
4.2.9 Inviting PINX : Any PINX in the connection that is associated with the ANF-PR user and able to request either end PINX
to invoke ANF-PR.
5 List of acronyms
ANF Additional Network Feature
ANF-PR Path Replacement additional network feature
APDU Application Protocol Data Unit
ASN.1 Abstract Syntax Notation no. 1
ISDN Integrated Services Digital Network
NFE Network Facility Extension
PICS Protocol Implementation Conformance Statement
PINX Private Integrated Services Network Exchange
PISN Private Integrated Services Network
SDL Specification and Description Language
SS-CT Call Transfer supplementary service
6 Signalling protocol for the support of ANF-PR
6.1 ANF-PR description
ANF-PR is invoked by an established call, allowing that call's connection through the PISN to be replaced by a new connection.
Optionally, the direction of the new connection may be decided by the ANF-PR user. If the new connection is required to satisfy
certain criteria, ANF-PR should be used in conjunction with other supplementary services and/or ANFs. In the absence of
specific criteria, the new connection should be established using the routeing rules which apply to basic call establishment.
Note 3 - Annex A of ISO/IEC 13863 gives examples of the circumstances under which ANF-PR can be used and criteria which can govern the selection of the
new connection.
ANF-PR may be initiated locally at the Requesting PINX or optionally from an Inviting PINX. The Requesting PINX shall
request the Cooperating PINX to attempt the establishment of a new connection from the Cooperating PINX to the Requesting
PINX. If successful, the new connection shall replace the old connection.
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Note 4 - The Requesting PINX can be either end PINX involved in a call, i.e., the Originating PINX or the Terminating PINX or, in the case of interworking
with another network, the Incoming Gateway PINX or Outgoing Gateway PINX.
Optional procedures and coding are specified for allowing the retention of one or more elements of the old connection, starting
from the Cooperating PINX and continuing as far as a Transit PINX, subject to any given criteria being achievable in that way.
A new connection is established from the Transit PINX to the Requesting PINX instead of from the Cooperating PINX to the
Requesting PINX.
6.2 ANF-PR operational requirements
6.2.1 Requirements on the Cooperating PINX
ANF-PR shall be applicable to a call whose protocol control state, as defined in ISO/IEC 11572, is Active.
Note 5 - State Active will have been reached as a result of ISO/IEC 11572 call establishment procedures, possibly in conjunction with supplementary service
and/or ANF procedures.
ISO/IEC 11572 protocol control procedures for call establishment at the outgoing side of an inter-PINX link shall apply to the
establishment of the new connection. ISO/IEC 11572 protocol control procedures for call clearing shall apply to the release of
the old connection in the event of successful switch over to the new connection.
Generic procedures for the call-related control of supplementary services, as specified in ISO/IEC 11582 for an end PINX, shall
apply.
6.2.2 Requirements on the Requesting PINX
ANF-PR shall be applicable to a call whose protocol control state, as defined in ISO/IEC 11572, is Active.
Note 6 - State Active will have been reached as a result of ISO/IEC 11572 call establishment procedures, possibly in conjunction with supplementary service
and/or ANF procedures.
ISO/IEC 11572 protocol control procedures for call establishment at the incoming side of an inter-PINX link shall apply to the
establishment of the new connection. ISO/IEC 11572 protocol control procedures for call clearing shall apply to the release of
the old connection in the event of successful switch over to the new connection.
Generic procedures for the call-related control of supplementary services, as specified in ISO/IEC 11582 for an end PINX, shall
apply.
6.2.3 Requirements on a Transit PINX
6.2.3.1 Transit PINX involved in the replaced connection
ANF-PR shall be applicable to a call whose protocol control state, as defined in ISO/IEC 11572, on each of the two links
(incoming and outgoing) is Active and whose call control state, as defined in ISO/IEC 11572 is TCC_Call_Active.
Note 7 - State Active will have been reached as a result of ISO/IEC 11572 call establishment procedures, possibly in conjunction with supplementary service
and/or ANF procedures.
ISO/IEC 11572 protocol control and call control procedures for call clearing at a Transit PINX shall apply to the release of the
old connection in the event of successful switch over to the new connection.
Generic procedures for the call-related control of supplementary services, as specified in ISO/IEC 11582 for a Transit PINX,
shall apply. For ANF-PR the requirements are limited to the passing on of Facility information elements for which the
destination, as indicated in the Network Facility Extension (NFE), is not the Transit PINX.
6.2.3.2 Transit PINX involved in the new connection
ISO/IEC 11572 protocol control and call control procedures for call establishment at a Transit PINX shall apply to the
establishment of the new connection.
ISO/IEC 11572 protocol control and call control procedures for call clearing at a Transit PINX shall apply to the release of the
new connection in the event of failure to complete ANF-PR successfully.
Generic procedures for the call-related control of supplementary services, as specified in ISO/IEC 11582 for a Transit PINX,
shall apply. For ANF-PR the requirements are limited to the passing on of Facility information elements for which the
destination, as indicated in the Network Facility Extension (NFE), is not the Transit PINX.
6.2.3.3 Transit PINX involved in the retained connection
The procedures below are applicable only if the optional procedures for retention of part of the old connection (0) are support ed.
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ANF-PR shall be applicable to a call whose protocol control state, as defined in ISO/IEC 11572, on each of the two links
(incoming and outgoing) is Active and whose call control state, as defined in ISO/IEC 11572 is TCC_Call_Active.
Note 8 - State Active will have been reached as a result of ISO/IEC 11572 call establishment procedures, possibly in conjunction with supplementary service
and/or ANF procedures.
Generic procedures for the call-related control of supplementary services, as specified in ISO/IEC 11582 for a Transit PINX,
shall apply.
6.2.3.4 Branching PINX
The procedures below are applicable only if the optional procedures for retention of part of the old connection (0) are support ed.
ANF-PR shall be applicable to a call whose protocol control state, as defined in ISO/IEC 11572, on each of the two links
(incoming and outgoing) is Active and whose call control state, as defined in ISO/IEC 11572 is TCC_Call_Active.
Note 9 - State Active will have been reached as a result of ISO/IEC 11572 call establishment procedures, possibly in conjunction with supplementary service
and/or ANF procedures.
ISO/IEC 11572 protocol control procedures for call establishment at the outgoing side of an inter-PINX link shall apply to the
establishment of the new connection. ISO/IEC 11572 protocol control procedures for call clearing shall apply to the release of
the replaced connection in the event of successful switch over to the new connection.
Generic procedures for the call-related control of supplementary services, as specified in ISO/IEC 11582 for a Transit PINX,
shall apply.
6.2.4 Requirements on the Inviting PINX
ANF-PR shall be applicable to a call whose protocol control state, as defined in ISO/IEC 11572, is Active. Generic procedures
for the call-related control of supplementary services, as specified in ISO/IEC 11582 for an end PINX, shall apply.
6.3 ANF-PR coding requirements
6.3.1 Operations
The operations defined in Abstract Syntax Notation number 1 (ASN.1) in table 1 shall apply.
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Table 1 - Operations in support of ANF-PR
Path-Replacement-Operations
{iso standard pss1-path-replacement (13874) pr-operations (0)}
DEFINITIONS EXPLICIT TAGS ::=
BEGIN
IMPORTS OPERATION, ERROR FROM Remote-Operation-Notation
{joint-iso-ccitt(2) remote-operations(4) notation (0)}
Extension FROM Manufacturer-specific-service-extension-definition
{iso standard
pss1-generic-procedures (11582) msi-definition (0)}
notAvailable, supplementaryServiceInteractionNotAllowed
FROM General-Error-List
{ccitt recommendation q 950 general-error-list (1)}
PartyNumber FROM Addressing-Data-Elements
{iso(1) standard(0) pss1-generic-procedures(11582)
addressing-data-elements(9)};
PathReplaceInvite ::= OPERATION
ARGUMENT DummyArg
ERRORS {
notAvailable,
temporarilyUnavailable,
supplementaryServiceInteractionNotAllowed,
criteriaPermanentlyUnachievable,
criteriaTemporarilyUnachievable,
invalidRerouteingNumber,
unrecognizedCallIdentity,
establishmentFailure,
collision,
unspecified
}
PathReplacePropose ::= OPERATION
ARGUMENT PRProposeArg
ERRORS {
notAvailable,
temporarilyUnavailable,
supplementaryServiceInteractionNotAllowed,
criteriaPermanentlyUnachievable,
criteriaTemporarilyUnachievable,
invalidRerouteingNumber,
unrecognizedCallIdentity,
establishmentFailure,
collision,
unspecified
}
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Table 1 - Operations in support of ANF-PR (continued)
PathReplaceSetup ::= OPERATION
ARGUMENT PRSetupArg
RESULT DummyResult
ERRORS {
criteriaPermanentlyUnachievable,
criteriaTemporarilyUnachievable,
invalidRerouteingNumber,
unrecognizedCallIdentity,
temporarilyUnavailable,
unspecified
}
PathReplaceRetain ::= OPERATION
ARGUMENT PRRetainArg
RESULT DummyResult
ERRORS {
notAvailable,
temporarilyUnavailable,
supplementaryServiceInteractionNotAllowed,
criteriaPermanentlyUnachievable,
criteriaTemporarilyUnachievable,
invalidRerouteingNumber,
unrecognizedCallIdentity,
establishmentFailure,
unspecified
}
PRProposeArg ::= SEQUENCE {
callIdentity CallIdentity,
rerouteingNumber PartyNumber,
extension CHOICE {
[1] IMPLICIT Extension,
[2] IMPLICIT SEQUENCE OF Extension
} OPTIONAL
}
PRSetupArg ::= SEQUENCE {
callIdentity CallIdentity,
extension CHOICE {
[1] IMPLICIT Extension,
[2] IMPLICIT SEQUENCE OF Extension
} OPTIONAL
}
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Table 1 - Operations in support of ANF-PR (continued)
PRRetainArg ::= SEQUENCE {
callIdentity CallIdentity,
rerouteingNumber PartyNumber,
extension CHOICE {
[1] IMPLICIT Extension,
[2] IMPLICIT SEQUENCE OF Extension
} OPTIONAL
}
DummyResult ::= CHOICE {
NULL,
[1] IMPLICIT Extension,
[2] IMPLICIT SEQUENCE OF Extension
}
DummyArg ::= CHOICE {
NULL,
[1] IMPLICIT Extension,
[2] IMPLICIT SEQUENCE OF Extension
}
CallIdentity ::= NumericString (SIZE(1.4))
pathReplacePropose PathReplacePropose ::= 4
pathReplaceSetup PathReplaceSetup ::= 5
pathReplaceRetain PathReplaceRetain ::= 6
pathReplaceInvite PathReplaceInvite::= 86
temporarilyUnavailable
ERROR ::= 1000
-- used when the operation is temporarily not available and none of
-- the other errors applies - a later attempt could be successful
collision ERROR ::= 1001
-- used when a pathReplacePropose invoke APDU is received by a PINX
-- which has sent a pathReplacePropose invoke APDU
criteriaPermanentlyUnachievable
ERROR ::= 1002
-- used when the special criteria requested cannot be achieved
-- because the necessary resources are permanently unavailable
criteriaTemporarilyUnachievable
ERROR ::= 1003
-- used when the special criteria requested cannot be achieved
-- because the necessary resources are temporarily unavailable
-- a later attempt could be successful
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Table 1 - Operations in support of ANF-PR (concluded)
invalidRerouteingNumber
ERROR ::= 1004
-- used when the establishment of the new connection fails because the
-- Called party number information element is not a valid number for
-- routeing the new connection to
unrecognizedCallIdentity
ERROR ::= 1005
-- used when establishment of the new connection fails because it could
-- not be associated with the old connection at the Requesting PINX
establishmentFailure
ERROR ::= 1006
-- used when establishment of the new connection fails and no other error
-- applies
Unspecified ::= ERROR PARAMETER Extension
unspecified Unspecified ::= 1008
-- used to convey a manufacturer specific error, possibly with other information
-- of Path-Replacement-Operations
END
6.3.2 Information elements
6.3.2.1 Facility information element
APDUs of the operations defined in 6.3.1 shall be coded in the Facility information element in accordance with ISO/IEC 11582.
When conveying the invoke APDU of operation PathReplaceInvite, the NFE shall be included and the destinationEntity data
element of the NFE shall contain value endPINX.
When conveying APDUs of operations pathReplacePropose and pathReplaceSetup, the NFE shall be included.
When conveying the invoke APDU of operation pathReplacePropose, the destinationEntity data element of the NFE shall
contain value endPINX.
When conveying the invoke APDU of operation pathReplaceSetup, the destinationEntity data element of the NFE shall contain
value endPINX.
When conveying the invoke APDU of operation pathReplaceRetain, the NFE shall be omitted.
When conveying the invoke APDU of operation pathReplaceSetup, the Interpretation APDU shall be included and shall have the
value clearCallIfAnyInvokePduNotRecognised. When conveying any other Remote Operations APDU, the Interpretation APDU
shall either be omitted or have the value rejectAnyUnrecognisedInvokePdu.
6.3.2.2 Other information elements
The following information elements used during establishment of the new connection and release of the old connection shall be
coded as specified in ISO/IEC 11572:
− Bearer capability
− Called party number
− Cause
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− Sending complete
The following information element shall be coded as specified in ISO/IEC 15056:
− Transit Counter
6.3.3 Messages
Except for cases where a basic call message is to be conveyed at the same time, the Facility information shall be conveyed in a
FACILITY message as specified in ISO/IEC 11582.
The following messages used during establishment of the new connection and release of the old connection shall be as specified
in ISO/IEC 11572:
− CALL PROCEEDING
CONNECT
−
− CONNECT ACKNOWLEDGE
− DISCONNECT
− RELEASE
− RELEASE COMPLETE
− SETUP
6.4 ANF-PR state definitions
6.4.1 States at the Requesting PINX
The procedures for the Requesting PINX are written in terms of the following conceptual states existing within the ANF-PR
functional entity in that PINX in association with a particular call.
6.4.1.1 State PR-Req-Idle
ANF-PR is not operating.
6.4.1.2 State PR-Req-Initiated
A pathReplacePropose invoke APDU has been sent to the Cooperating PINX.
6.4.1.3 State PR-Req-Completing
The new connection has been established and a pathReplaceSetup return result APDU has been sent to the Cooperating PINX.
6.4.2 States at the Cooperating PINX
The procedures for the Cooperating PINX are written in terms of the following conceptual states existing within the ANF-PR
functional entity in that PINX in association with a particular call.
6.4.2.1 State PR-Coop-Idle
ANF-PR is not operating.
6.4.2.2 State PR-Coop-Establishment
A pathReplaceSetup invoke APDU has been sent in conjunction with the establishment of the new connection.
6.4.2.3 State PR-Coop-Retain
A pathReplaceRetain invoke APDU has been sent to the subsequent PINX.
6.4.3 States at a Transit PINX on the retained path, including the branching PINX
The procedures for a Transit PINX on the retained path are written in terms of the following conceptual states existing within the
ANF-PR functional entity in that PINX in association with a particular call.
6.4.3.1 State PR-Transit-Idle
ANF-PR is not operating.
6.4.3.2 State PR-Transit-Establishment
A pathReplaceSetup invoke APDU has been sent in conjunction with the establishment of the new connection.
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6.4.3.3 State PR-Transit-Retain
A pathReplaceRetain invoke APDU has been sent to the subsequent PINX.
6.4.4 States at the Inviting PINX
6.4.4.1 State PR-invite-Idle
ANF-PR is not operating.
6.5 ANF-PR signalling procedures
The signalling procedures specified below are in support of replacement of the entire connection. Additional optional procedures
for retention of part of the old connection are specified in 6.6.
Examples of message sequences are shown in C.1 to C.4 of annex C.
6.5.1 Actions at the Requesting PINX
The SDL representation of procedures at the Requesting PINX is shown in D.2 of annex D.
6.5.1.1 ANF PR initiated by the Requesting PINX
The procedures of 6.5.1.3 and 6.5.1.4 shall apply.
6.5.1.2 Optional support of a request from an Inviting PINX
On receipt of a FACILITY message containing a pathReplaceInvite invoke APDU, the Requesting PINX shall apply the
procedures of 6.5.1.3 and 6.5.1.4 with the following additions.
If the Requesting PINX is unable to act on the pathReplaceInvite invoke APDU while in state PR-Req-Idle, a FACILITY
message containing pathReplaceInvite return error APDU may be returned. No state change shall occur.
While in state PR-Req-Initiated or PR-Req-Completing, a FACILITY message containing a pathReplaceInvite invoke shall be
ignored.
On receipt of a FACILITY message containing a pathReplacePropose return error while in state PR-Req-Initiated, a
PathReplaceInvite return error APDU may be returned to the Inviting PINX.
6.5.1.3 Normal procedures
Examples of message sequences are shown in C.1 and C.3 of annex C.
The Requesting PINX shall send a pathReplacePropose invoke APDU in a FACILITY message to the Cooperating PINX and
enter state PR-Req-Initiated. Within the argument, the rerouteingNumber data element shall contain a number from one of the
native number plans of the PISN (see ISO/IEC 11571). The number, when used as the contents of information element Called
party number in a SETUP message, shall be sufficient to cause routeing of the new connection to the Requesting PINX. The
callIdentity data element shall contain a number which, in conjunction with the rerouteingNumber data element, identifies the
particular ANF-PR entity, and therefore the call on which ANF-PR is being invoked. This number need not have significance
outside the Requesting PINX.
Note 10 - The number in the callIdentity data element should be sufficient to distinguish the call concerned from any other call for which the PINX is acting as
an ANF-PR Requesting PINX at that time.
Having agreed the B-channel and sent back a CALL PROCEEDING message in response to an incoming SETUP message, in
accordance with the procedures of ISO/IEC 11572, if the SETUP contains a pathReplaceSetup invoke APDU the Requesting
PINX shall proceed as follows. If the callIdentity data element in the argument of pathReplaceSetup, in conjunction with the
number information in the Called party number information element, identifies an ANF-PR entity in state PR-Req-Initiated, the
Requesting PINX shall associate the new connection (as requested by the SETUP message) with the call on whose behalf that
ANF-PR entity is acting.
The Requesting PINX shall connect the calling / called user to the B-channel of the new connection and terminate the B-channel
of the old connection in a suitable manner (pending its release).
Note 11 - The method of terminating the old connection's B-channel is an implementation matter. Annex B of ISO/IEC 13863 contains more information on
this.
A pathReplaceSetup return result APDU shall be sent in a CONNECT message using the call reference of the new connection
and state PR-Req-Completing shall be entered.
Note 12 - On sending CONNECT, the protocol control state for the new connection will become Active.
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While in state PR-Req-Completing, if a DISCONNECT message is received using the call reference of the old connection, the
Requesting PINX shall complete the release of the old connection in accordance with the procedures of ISO/IEC 11572, and
enter state PR-Req-Idle. The call shall continue as an active call using the new connection.
6.5.1.4 Exceptional procedures
Examples of message sequences are shown in C.2 and C.4 of annex C.
Receipt of a FACILITY message containing a pathReplacePropose return error APDU or reject APDU during state PR-Req-
Initiated shall cause entry to state PR-Req-Idle, thereby abandoning ANF-PR. The call shall continue to use the old connection.
Note 13 - Depending on the error, it may be appropriate to invoke ANF-PR again later. If the error is collision, steps should be taken to reduce the probability
of a further collision, e.g., by using a random delay before invoking again.
Failure to associate an incoming SETUP message containing a pathReplaceSetup invoke APDU with an ANF-PR entity in state
PR-Req-Initiated shall result in the sending of a DISCONNECT message to initiate the clearing of the new connection.
Depending on implementation, the DISCONNECT message shall contain either:
− a suitable cause number in the Cause information element, e.g., 1 "unallocated (unassigned) number"; or
− cause number 29 "facility rejected" in the Cause information element and a return error APDU containing error
invalidRerouteingNumber; or
− cause number 29 "facility rejected" in the Cause information element and a return error APDU containing error
unrecognizedCallIdentity.
If the incoming SETUP message containing a pathReplaceSetup invoke APDU is successfully associated with an ANF-PR entity
in state PR-Req-Initiated but the new connection is unsuitable for some reason, e.g., criteria not satisfied, a DISCONNECT
message shall be sent to initiate clearing of the new connection. The DISCONNECT message shall contain cause number 29
"facility rejected" in the Cause information element and a return error APDU containing an appropriate error. The ANF-PR
entity shall remain in state PR-Req-Initiated.
Note 14 - Receipt of a pathReplacePropose return error APDU can be expected.
On receipt of a FACILITY message containing a pathReplacePropose invoke APDU while in state PR-Req-Initiated, a
pathReplacePropose return error APDU containing error collision shall be returned. No state change shall occur.
Note 15 - Receipt of a pathReplacePropose return error APDU containing error collision can be expected.
While in state PR-Req-Completing, if a DISCONNECT message is received using the call reference of the new connection, the
Requesting PINX shall complete the release of the new connection in accordance with the procedures of ISO/IEC 11572,
reconnect the calling / called user to the B-channel of the old connection, and enter state PR-Req-Idle.
6.5.2 Actions at the Cooperating PINX
The SDL representation of procedures at the Cooperating PINX is shown in D.3 of annex D.
6.5.2.1 Normal procedures
On receipt of a FACILITY message containing a pathReplacePropose invoke APDU while in protocol control state Active and
ANF-PR state PR-Coop-Idle, the Cooperating PINX shall determine whether it can proceed with ANF-PR. If so, it shall attempt
to establish a new connection by selecting an outgoing B-channel on a route determined by the contents of the rerouteingNumber
data element within the received argument. If a B-channel is available, a SETUP message shall be sent using a new call reference
in accordance with the procedures of ISO/IEC 11572. The SETUP shall contain a new call reference and the following
information elements.
− Bearer capability, containing bearer capability information as for the old connection;
− Called party number, containing the number received in the rerouteingNumber data element within the - received argument;
− Sending complete;
− Facility.
− Optionally, Transit Counter with the transit count field set to zero
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The Facility information element shall contain a pathReplaceSetup invoke APDU. Within the argument, data element
callIdentity shall have the same contents as the corresponding data element in the argument of the received pathReplacePropose
invoke APDU.
The Cooperating PINX shall terminate the new connection's B-channel suitably.
Note 16 - The method of terminating the new connection's B-channel is an implementation matter. Annex B of ISO/IEC 13863 contains more information on
this.
State PR-Coop-Establishment shall be entered.
The protocol control procedures of ISO/IEC 11572 shall apply during the establishment of the new connection.
Note 17 - Initially protocol control will enter state Call Initiated. On receipt of a CALL PROCEEDING message, state Outgoing Call Proceeding will be
entered and on receipt of CONNECT, state Active will be entered.
On receipt of a CONNECT message (using the call reference of the new connection) containing a pathReplaceSetup return result
APDU, the Cooperating PINX shall disconnect the B-channel of the old connection and connect the calling / called user instead
to the B-channel of the new connection. A DISCONNECT message shall be sent using the call reference of the old connection,
thereby initiating the clearing procedures of ISO/IEC 11572 for the old connection. State PR-Coop-Idle shall be entered. The call
shall continue as an active call using the new connection.
6.5.2.2 Exceptional procedures
If the Cooperating PINX is unable to comply with the pathReplacePropose invoke APDU, it shall send back a FACILITY
message containing a pathReplacePropose return error APDU with a suitable error.
If the new connection fails to be established for any reason, the Cooperating PINX shall send using the old connection a
FACILITY message containing a pathReplacePropose return error APDU with a suitable error. Reasons can include:
− unable to select a B-channel for the new connection;
− receipt of a call clearing message using the new connection's call reference without a pathReplaceSetup return error APDU or
reject APDU;
− receipt of a call clearing message using the new connection's call reference with a pathReplaceSetup return error APDU or
reject APDU;
− timer expiry at the Cooperating PINX.
In each case state PR-Coop-Idle shall be entered and the call shall continue as an active call using the old connection.
On receipt of a FACILITY message containing a pathReplaceInvite invoke APDU while in state PR-Coop-Retain or PR-Coop-
Establishment, a FACILITY message containing a pathReplaceInvite return error APDU may be returned to the Inviting PINX.
No state change should occur.
6.5.3 Actions at a Cooperating/Requesting PINX in the case of a trombone connection
On receipt of a FACILITY message containing a pathReplacePropose invoke APDU, the Cooperating PINX can determine from
the rerouteingNumber data element in the argument whether the Requesting PINX is the same as the Cooperating PINX, i.e.,
whether a trombone connection exists.
In the case of a trombone connection, establishment of the new connection and switching over to it will be intra-PINX matters.
The only further signalling which will occur at the Q reference point will be the clearing of the old connection.
6.5.4 Actions at a Transit PINX
No special actions are required in support of ANF-PR.
6.5.5 Actions at Inviting PINX
The SDL representation of procedures at the Inviting PINX is shown in D.1 of annex D.
6.5.5.1 Normal procedures
On determining that ANF-PR is to be invoked during a call whose protocol control state is Active, the Inviting PINX shall send a
pathReplaceInvite invoke APDU in a FACILITY message to the Requesting PINX. If the old connection is cleared it shall be
interpreted as ANF-PR is successful.
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6.5.5.2 Exceptional procedures
On receipt of a FACILITY message containing a pathReplaceInvoke return error or reject APDU the action shall be
implementation dependent.
Note 18 - Depending on the error, it may be appropriate to invoke ANF-PR again later or invoke ANF-PR in the other direction. If the error is collision, steps
should be taken to reduce the probability of a further collision, e.g., by using a random delay before invoking again.
6.6 ANF-PR optional signalling procedures for retention of part of the old connection
Examples of message sequences are shown in C.5 to C.7 of annex C.
6.6.1 Actions at the Requesting PINX
The procedures of 6.5.1 shall apply, with the following addition.
If the Requesting PINX receives a FACILITY message containing a pathReplaceRetain invoke APDU from the preceding PINX,
it shall send back a FACILITY message containing a pathReplaceRetain return result APDU and enter state PR-Req-Idle.
6.6.2 Actions at the Cooperating PINX
The SDL representation of procedures at the Cooperating PINX, including optional retention of part of the old connection, is
shown in D.3 of annex D.
6.6.2.1 Normal procedures
On receipt of a FACILITY message containing a pathReplacePropose invoke APDU while in protocol control state Active and
ANF-PR state PR-Coop-Idle, the Cooperating PINX shall determine whether it can proceed with ANF-PR, and whether it can
retain that part of the old connection as far as the subsequent PINX while still meeting any given criteria. If so, it shall send a
FACILITY message containing a pathReplaceRetain invoke APDU to the subsequent PINX and enter state PR-Coop-Retain.
The rerouteingNumber and callIdentity data elements shall have the same contents as the corresponding data elements received
in the pathReplacePropose invoke APDU.
Note 19 - The omission of the NFE from the Facility information element ensures that the APDU will be processed by the subsequent PINX. If the subsequent
PINX does not support these optional procedures it will send back a reject APDU.
If it cannot retain that part of the old connection as far as the subsequent PINX it shall proceed according to the provisions of
6.5.2.
On receipt of a FACILITY message containing a pathReplaceRetain return result APDU from the subsequent PINX, the
Cooperating PINX shall enter state PR-Coop-Idle.
6.6.2.2 Exceptional procedures
On receipt of a FACILITY message containing a pathReplaceRetain return error APDU or reject APDU from the subsequent
PINX while in state PR-Coop-Retain, the Cooperating PINX shall either, depending on the reason for the error or reject APDU:
− proceed according to the provisions of 6.5.2, as if there had been no attempt to retain part of the old connection; or
− send back a FACILITY message containing a pathReplacePropose return error APDU with a suitable error to the Requesting
PINX and enter state PR-Coop-Idle.
6.6.3 Actions at a Transit PINX on the retained connection
The SDL representation of procedures at a Transit PI
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