SIST ETS 300 258 E1:2005

Private Telecommunication Network (PTN); Specification, functional models and information flows; Path replacement additional network feature

Contains stage 1 and 2 description of additional network feature path replacement.  See ECMA DTR/ECMA-002 (ECMA-TR/SVC) for a description of the additional network feature path replacement. See ENV 41 005 for definition of stage 1 and 2

Zasebno telekomunikacijsko omrežje (PTN) – Specifikacija, funkcijski modeli in informacijski pretoki - Dodatna omrežna lastnost (ANF): nadomestitev poti

General Information

• Status: Published
• Publication Date: 30-Apr-2005
• ICS: 33.040.35 - Telephone networks
• Technical Committee: SPN - Services and Protocols for Networks
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 01-May-2005
• Due Date: 01-May-2005
• Completion Date: 01-May-2005
• Ref Project: ETSI ETS 300 258 ed.1 (1993-11) - Private Telecommunication Network (PTN); Specification, functional models and information flows; Path replacement additional network feature

Standards Content (Sample)

SLOVENSKI STANDARD
SIST ETS 300 258 E1:2005
01-maj-2005
Zasebno telekomunikacijsko omrežje (PTN) – Specifikacija, funkcijski modeli in
informacijski pretoki - Dodatna omrežna lastnost (ANF): nadomestitev poti
Private Telecommunication Network (PTN); Specification, functional models and
information flows; Path replacement additional network feature
Ta slovenski standard je istoveten z: ETS 300 258 Edition 1
ICS:
33.040.35 Telefonska omrežja Telephone networks
SIST ETS 300 258 E1:2005 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST ETS 300 258 E1:2005

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SIST ETS 300 258 E1:2005
EUROPEAN ETS 300 258
TELECOMMUNICATION November 1993
STANDARD
Source: ETSI TC-ECMA Reference: DE/ECMA-00014
ICS: 33.080
PTN, ECMA-175, PRSD
Key words:
Private Telecommunication Network (PTN);
Specification, functional models and information flows
Path replacement additional network feature
ETSI
European Telecommunications Standards Institute
ETSI Secretariat
Postal address: F-06921 Sophia Antipolis CEDEX - FRANCE
Office address: 650 Route des Lucioles - Sophia Antipolis - Valbonne - FRANCE
X.400: c=fr, a=atlas, p=etsi, s=secretariat - Internet: [e-mail]
Tel.: [phone] - Fax: [phone]
No part may be reproduced except as authorized by written permission. The copyright and the
Copyright Notification:
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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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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Table of contents
Foreword 7
1Scope 9
2 Conformance 9
3 References 9
4 Definitions 10
4.1 External definitions 10
4.2 Additional network feature 10
4.3 ANF-PR user 10
4.4 Call, basic call 10
4.5 Connection 10
4.6 New connection 10
4.7 Old connection 11
4.8 Trombone connection 11
5 List of acronyms 11
6 ANF-PR stage 1 specification 11
6.1 Description 11
6.1.1 General description 11
6.1.2 Qualifications on applicability to telecommunication services 11
6.2 Procedure 11
6.2.1 Provision/withdrawal 11
6.2.2 Normal procedures 12
6.2.2.1 Activation/deactivation/registration/interrogation 12
6.2.2.2 Invocation and operation 12
6.2.3 Exceptional procedures 12
6.2.3.1 Activation/deactivation/registration/interrogation 12
6.2.3.2 Invocation and operation 12
6.3 Interaction with other supplementary services and ANFs 12
6.3.1 Identification supplementary services (Calling Line Identification
Presentation, Connected Line Identification Presentation, and
Calling/Connected Line Identification Restriction) 12
6.3.2 Name Identification supplementary services (Calling Name
Identification Presentation, Connected Name Identification
Presentation, Calling/Connected Name Identification Restriction) 12
6.3.3 Call Forwarding supplementary services (Call Forwarding
Unconditional, Call Forwarding on Busy, Call Forwarding on No
Reply) 13
6.3.4 Call Transfer supplementary service 13
6.4 Interworking considerations 13
6.5 Overall SDL 13
7 ANF-PR stage 2 specification - basic operation 14
7.1 Functional model 14
7.1.1 Functional model description 14
7.1.2 Description of functional entities 14
7.1.2.1 Path replacement destination functional entity, FE1 14

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7.1.2.2 Path replacement source functional entity, FE2 14
7.1.3 Relationship of functional model to basic call functional model 14
7.2 Information flows 15
7.2.1 Definition of information flows 15
7.2.1.1 PRP (Path Replacement Propose) 15
7.2.1.2 PRS (Path Replacement Setup) 15
7.2.1.3 PRE (Path Replacement Error) 16
7.2.2 Relationship of information flows to basic call information flows 16
7.2.3 Examples of information flow sequences 16
7.2.3.1 Normal operation of ANF-PR 17
7.2.3.2 Failure to establish new connection 18
7.3 Functional entity actions 18
7.3.1 Functional entity actions of FE1 19
7.3.2 Functional entity actions of FE2 19
7.4 Functional entity behaviour 19
7.4.1 Behaviour of FE1 19
7.4.2 Behaviour of FE2 21
7.5 Allocation of functional entities to physical equipment 22
7.6 Interworking considerations 22
8 ANF-PR stage 2 specification - re-use of connection elements 23
8.1 Functional model 23
8.1.1 Functional model description 23
8.1.2 Description of functional entities 23
8.1.2.1 Path replacement destination functional entity, FE1 23
8.1.2.2 Path replacement source functional entity, FE2 23
8.1.2.3 Path replacement re-use functional entity, FE3 23
8.1.3 Relationship of functional model to basic call functional model 23
8.2 Information flows 24
8.2.1 Definition of information flows 24
8.2.1.1 PRP (Path Replacement Propose) 24
8.2.1.2 PRS (Path Replacement Setup) 24
8.2.1.3 PRE (Path Replacement Error) 24
8.2.1.4 PRR (Path Replacement Re-use) 24
8.2.2 Relationship of information flows to basic call information flows 25
8.2.3 Examples of information flow sequences 25
8.2.3.1 Normal operation of ANF-PR with re-use of part of old
connection 26
8.2.3.2 Failure to establish new connection to replace part of old
connection 27
8.2.3.3 Retention of all of the old connection 28
8.3 Functional entity actions 28
8.3.1 Functional entity actions of FE1 28
8.3.2 Functional entity actions of FE2 28
8.3.3 Functional entity actions of FE3 29
8.4 Functional entity behaviour 29
8.4.1 Behaviour of FE1 29
8.4.2 Enhanced behaviour of FE2 29
8.4.3 Behaviour of FE3 30
8.5 Allocation of functional entities to physical equipment 32
8.6 Interworking considerations 32

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Annex A (informative): Circumstances in which ANF-PR might be invoked 33
A.1 Cost reduction 33
A.2 Change of bearer capability 34
A.3 Quality of service improvement 34
A.4 Maintenance actions 34
Annex B (informative): Avoidance of unacceptable disruption to user information 35
B.1 Methods of handling user information channels 35
B.1.1 Simultaneous switchover of both directions of transmission 35
B.1.2 Separate switchover of each direction of transmission 35
B.1.3 Mixed operation 35
B.2 Preventing the use of ANF-PR 36
B.3 Replacement of trombone connections 36
History 37

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Foreword
This European Telecommunication Standard (ETS) has been produced by the European Computer Manufacturers
Association (ECMA) on behalf of its members and those of the European Telecommunications Standards Institute
(ETSI).
This ETS is one of a series of standards defining services and signalling protocols applicable to Private
Telecommunication Networks (PTNs). The series uses the ISDN concepts as developed by CCITT and is also within the
framework of standards for open systems interconnection as defined by ISO.
This ETS specifies the Path Replacement additional network feature.
The ETS is based upon the practical experience of ECMA member companies and the results of their active and
continuous participation in the work of ISO, CCITT, ETSI and other international and national standardisation bodies.
It represents a pragmatic and widely based consensus.
This ETS was produced by ECMA using the ECMA guidelines for the production of standards and using the ECMA
stylesheet. In order to avoid undue delays in the voting process of this ETS it has been agreed that this ETS will not be
converted to the ETSI stylesheet.

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1Scope
This ETS specifies the Path Replacement additional network feature (ANF-PR), which is applicable to various
basic services supported by Private Telecommunication Networks (PTNs). Basic services are specified in ETS
300 171.
ANF-PR is a feature which applies to an established call, allowing that call's connection between Private
Telecommunication Network Exchanges (PTNXs) to be replaced by a new connection. If the new connection is
required to satisfy certain criteria, ANF-PR should be used in conjunction with other supplementary services
and/or ANFs. Annex A gives examples of the circumstances under which ANF-PR can be used and criteria
which can govern the selection of the new connection.
Additional network feature specifications are produced in three stages, according to the method described in
ENV 41005 for supplementary services. This ETS contains the stage 1 and stage 2 specifications of ANF-PR.
The stage 1 specification (clause 6) specifies the feature as seen by an entity which initiates path replacement,
the ANF-PR user. The stage 2 specification (clauses 7 and 8) identifies the functional entities involved in the
feature and the information flows between them. Clause 7 contains the stage 2 specification for basic operation
of the feature. Clause 8 contains the stage 2 specification for an enhanced mode of working which can be
employed when supported by all the equipment involved. It allows some of the elements of the old connection
to be re-used.
2 Conformance
In order to conform to this ETS, a stage 3 standard shall specify signalling protocols and equipment behaviour
that are capable of being used in a PTN which supports the feature specified in this ETS. This means that, to
claim conformance, a stage 3 standard is required to be adequate for the support of those aspects of clause 6
(stage 1) and clauses 7 and 8 (stage 2) which are relevant to the interface or equipment to which the stage 3
standard applies.
3 References
ENV 41005 Method for the specification of basic and supplementary services of private
telecommunication networks (1989)
ENV 41007 Definition of terms in private telecommunication networks (1989)
ETS 300 171 Private Telecommunication Network (PTN); Specification, functional models and
information flows, Control aspects of circuit mode basic services (1992)
ETS 300 189 Private Telecommunication Network (PTN); Addressing (1992)
CCITT Recommendation I.112 Vocabulary of terms for ISDNs (1988)
CCITT Recommendation I.210 Principles of telecommunication services supported by an ISDN
and the means to describe them (1988)
CCITT Recommendation Z.100 Specification and description language (1988)

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4 Definitions
For the purpose of this ETS the following definitions apply.
4.1 External definitions
This ETS uses the following terms defined in other documents:
- Basic service (CCITT Recommendation I.210);
- Private (ENV 41007);
- Private Telecommunication Network Exchange (PTNX) (ENV 41007);
- Service (CCITT Recommendation I.112);
- Signalling (CCITT Recommendation I.112);
- Supplementary Service (CCITT Recommendation I.210);
- Telecommunication Network (ENV 41007);
- User (except in the context of ANF-PR user) (ETS 300 171).
This ETS refers to the following basic call functional entities (FEs) defined in ETS 300 171:
- Call Control (CC);
- Call Control Agent (CCA).
This ETS refers to the following basic call inter-FE relationships defined in ETS 300 171:
-r1;
-r2;
-r3.
This ETS refers to the following basic call information flows defined in ETS 300 171:
- Channel_Acknowledge request/indication;
- Release request/indication;
- Release response/confirmation;
- Setup request/indication;
- Setup response/confirmation.
This ETS refers to the following basic call information flow element defined in ETS 300 171:
- Destination Number.
4.2 Additional network feature
A capability, over and above that of a basic service, provided by a PTN, but not directly to a PTN user.
4.3 ANF-PR user
An entity, within a PTN, that requests ANF-PR.
4.4 Call, basic call
An instance of the use of a basic service.
4.5 Connection
As defined in CCITT Recommendation I.112, but limited to the case of providing for the transfer of signals
between two PTNXs.
NOTE 1
A connection between two PTNXs can pass through zero or more Transit PTNXs.
4.6 New connection
The connection established by ANF-PR and used to replace all or part of the old connection.

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4.7 Old connection
The connection existing before ANF-PR is invoked.
4.8 Trombone connection
A connection which has both its ends in the same PTNX but which involves at least one Transit PTNX.
5 List of acronyms
ANF Additional Network Feature
ANF-PR ANF Path Replacement
CC Call Control (functional entity)
CCA Call Control Agent (functional entity)
CID Call Identity
FE Functional Entity
ISDN Integrated Services Digital Network
PRE Path Replacement Error
PRP Path Replacement Propose (information flow)
PRR Path Replacement Re-use (information flow)
PRRR PRR Result (information flow element)
PRS Path Replacement Setup (information flow)
PRSR PRS Result (information flow element)
PTN Private Telecommunication Network
PTNX Private Telecommunication Network Exchange
RN Rerouting Number (information flow element)
SDL Specification and Description Language
6 ANF-PR stage 1 specification
6.1 Description
6.1.1 General description
ANF-PR is invoked by an ANF-PR user for an established call, allowing that call's connection through the
PTN to be replaced by a new connection. If the new connection is required to satisfy certain criteria,
ANF-PR should be used in conjunction with other supplementary services and/or ANFs. Annex A gives
examples of the circumstances under which ANF-PR can be used and criteria which can govern the
selection of the new connection.
6.1.2 Qualifications on applicability to telecommunication services
This supplementary service is applicable to all basic services defined in ETS 300 171.
NOTE 2
For certain teleservices or certain applications of certain basic bearer services the changeover from the
old connection to the new connection can cause unacceptable disruption. See annex B.
6.2 Procedure
6.2.1 Provision/withdrawal
This ANF shall be PTN instigated.
NOTE 3
Means can be provided for preventing the use of ANF-PR for applications where the changeover from the
old connection to the new connection is likely to cause unacceptable disruption. See annex B.

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6.2.2 Normal procedures
6.2.2.1 Activation/deactivation/registration/interrogation
The feature shall be permanently activated.
6.2.2.2 Invocation and operation
Invocation shall be on request from an ANF-PR user and shall be permitted only after a call has reached
the active state.
On invocation an attempt shall be made to establish a new connection between the Originating PTNX
and the Terminating PTNX. In the absence of specific criteria, the new connection shall be established
using the routing rules which apply to basic call establishment. If the new connection is successfully
established it shall be used to replace the old connection, which shall be released.
Changeover from the old connection to the new connection should be done in a manner which
minimises disruption to user information.
NOTE 4
The means of specifying criteria and ensuring that the new connection satisfies those criteria can
involve the use of another ANF or supplementary service, which can be either standardized or
manufacturer specific.
In some circumstances it may be possible to re-use some elements of the old connection, so that only
part of the old connection has to be replaced by a new connection, subject to the given criteria being
achievable in that way.
6.2.3 Exceptional procedures
6.2.3.1 Activation/deactivation/registration/interrogation
Not applicable.
6.2.3.2 Invocation and operation
If it is not possible to establish a new connection, the call shall continue to use the old connection and
any resources reserved for the new connection shall be released. There shall be no disruption to user
information.
In the event of two ANF-users (at opposite ends of the connection) requesting the feature
simultaneously, both requests shall be rejected.
NOTE 5
An ANF-PR user can request the feature again later in the event of failure. In the case of failure due to
simultaneous requests, care should be taken to avoid a repeat occurrence, e.g. by use of a random
delay.
6.3 Interaction with other supplementary services and ANFs
Interactions with other supplementary services and ANFs for which PTN Standards were available at the
time of publication of this ETS are specified below.
6.3.1 Identification supplementary services (Calling Line Identification Presentation, Connected Line
Identification Presentation, and Calling/Connected Line Identification Restriction)
No interaction.
6.3.2 Name Identification supplementary services (Calling Name Identification Presentation, Connected
Name Identification Presentation, Calling/Connected Name Identification Restriction)
No interaction.

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6.3.3 Call Forwarding supplementary services (Call Forwarding Unconditional, Call Forwarding on Busy,
Call Forwarding on No Reply)
ANF-PR can apply to a call which has been forwarded.
6.3.4 Call Transfer supplementary service
If call transfer occurs while ANF-PR is in progress, ANF-PR shall be aborted.
ANF-PR can apply to a call which has been transferred. The fact that transfer has occurred can be a reason
for invoking ANF-PR (see annex A).
6.4 Interworking considerations
The requirements below apply to both incoming calls and outgoing calls.
It shall be possible to use ANF-PR on the PTN part of the connection. The new connection through the PTN
shall replace the old connection through the PTN.
When interworking with another network which supports an equivalent feature, it may be possible to
cooperate with the other network in order to replace the entire connection.
6.5 Overall SDL
Figure contains the dynamic description of ANF-PR using the Specification and Description Language
(SDL) defined in CCITT Recommendation Z.100 (1988). The SDL process represents the behaviour of the
PTN in providing ANF-PR. Input signals from the left and output signals to the left represent primitives from
and to the ANF-PR user.
IDLE
Initiate
ANF-PR
Establish
new connection
N
Successful?
Y
Switch to
new connection
Release any
resources for
new connection
Release old
connection
ANF-PR
Unsuccessful
ANF-PR
successful
IDLE
Figure 1 - ANF-PR, Overall SDL

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7 ANF-PR stage 2 specification - basic operation
7.1 Functional model
7.1.1 Functional model description
The functional model shall comprise the FEs "Path Replacement Destination" (FE1) and "Path
Replacement Source" (FE2). A relationship, rx, shall exist between FE1 and FE2. See figure 2.
PR
PR
DESTINATION SOURCE
rx
FE1
FE2
Figure 2 - Functional model for ANF-PR
7.1.2 Description of functional entities
7.1.2.1 Path replacement destination functional entity, FE1
This functional entity receives a request from the ANF-PR user to initiate ANF-PR and instructs FE2 to
attempt to establish a new connection back towards FE1. If the new connection is successfully
established, FE1 switches to the new connection and awaits the release of the old connection.
7.1.2.2 Path replacement source functional entity, FE2
On receipt of instruction from FE1 and if able to proceed with ANF-PR, this functional entity initiates
the establishment of a new connection back towards FE1. If the new connection is successfully
established, FE2 switches to the new connection and initiates release of the old connection.
7.1.3 Relationship of functional model to basic call functional model
During successful invocation of ANF-PR, the Transit CCs, if any, involved in the old connection shall be
replaced by the Transit CCs, if any, involved in the new connection. The Originating and Terminating
CCs shall remain.
For the case of a call originating and terminating within the PTN, ANF-PR functional entities shall be
related to basic call functional entities as follows:
- FE1 shall be collocated with the Originating CC or the Terminating CC, depending on the location of
the ANF-PR user;
- FE2 shall be collocated with the Terminating CC if FE1 is collocated with the Originating CC, or with
the Originating CC if FE1 is collocated with the Terminating CC.
Figure 3 shows an example of the relationship between the model for ANF-PR and the model for the basic
call. This example is used as the basis of the information flow sequences in 7.2.3.
NOTE 6
The number of Transit CCs on the new connection can differ from the number on the old connection.

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r2
CC
CC
Old Connection
r2
r2
r2 r2 r3
r2
r1
CCA CC CC CC CCA
CC
New Connection
FE1
FE2
rx
Figure 3 - Example relationship between models for ANF-PR and basic call
7.2 Information flows
7.2.1 Definition of information flows
In the tables listing the elements in information flows, the column headed "Request" indicates which of
these elements are mandatory (M) and which are optional (O) in a request/indication information flow,
and the column headed "Confirm" indicates which of these elements are mandatory (M) and which are
optional (O) in a response/confirmation information flow.
7.2.1.1 PRP (Path Replacement Propose)
PRP is an unconfirmed information flow across rx from FE1 to FE2 which proposes path replacement
to FE2.
PRP request/indication is sent using the signalling path of the old connection.
Table 1 lists the elements within the PRP information flow.
Table 1 - Content of PRP
Element Request
Rerouting Number (RN) M
Call Identity (CID) M
Element RN shall always be included in the PRP request/indication information flow at rx. It shall
contain a number from one of the native numbering plans of the PTN (see ETS 300 189). The number
shall be suitable for use for routing the new connection to the physical location where FE1 resides.
Element CID shall always be included in the PRP request/indication information flow at rx. It shall
contain a number which, in conjunction with the number in element RN, identifies the particular FE1,
and therefore the call on which ANF-PR is being invoked. This number need not have significance
outside the physical location where FE1 resides.
7.2.1.2 PRS (Path Replacement Setup)
PRS is a confirmed information flow across rx from FE2 to FE1 which indicates to FE1 that the new
connection being established is for the purpose of path replacement. The response indicates whether
FE1 has successfully correlated the new connection with the old connection and is prepared to switch to
the new connection.
PRS request/indication and PRS response/confirmation are sent using the signalling path of the new
connection at the time of establishment of that connection.
Table 2 lists the elements within the PRS information flow.

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Table 2 - Content of PRS
Element Request Confirm
Call Identity (CID) M -
PRS Result (PRSR) - M
Element CID shall always be included in the PRS request/indication information flow at rx. It shall
contain the value received in the corresponding element of the PRP request/indication information
flow.
Element PRSR shall always be included in the PRS response/confirmation information flow at rx. It
indicates whether the request was successful, and if not the reason for failure.
7.2.1.3 PRE (Path Replacement Error)
PRE is an unconfirmed information flow across rx from FE2 to FE1 which indicates to FE1 that path
replacement has failed.
Table 3 lists the elements within the PRE information flow.
Table 3 - Content of PRE
Element Request
Reason for failure M
7.2.2 Relationship of information flows to basic call information flows
The PRS request/indication information flow shall be sent in conjunction with the basic call information
flow Setup request/indication for the new connection sent across basic call relationship r2. Element
Destination Number of information flow Setup request/indication shall contain the number provided in
element RN of information flow PRP request/indication.
The PRS response/confirmation information flow shall be sent in conjunction with the basic call
information flow Setup response/confirmation for the new connection across basic call relationship r2.
Failure to establish the new connection shall result in the initiation of its release using basic call
information flow Release request/indication across relationship r2.
Successful switch over to the new connection shall result in the initiation of the release of the old
connection using basic call information flow Release request/indication across relationship r2.
7.2.3 Examples of information flow sequences
A stage 3 Standard for ANF-PR shall provide signalling procedures in support of the information flow
sequences specified below. In addition, signalling procedures should be provided to cover other sequences
arising from error situations, interactions with basic call, interactions with other supplementary services,
different topologies, etc.
In the figures, ANF-PR information flows are represented by solid arrows and basic call information flows
are represented by broken arrows. An ellipse embracing two information flows indicates that the two
information flows occur simultaneously. Within a column representing an ANF-PR functional entity, the
numbers refer to functional entity actions listed in 7.3.

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7.2.3.1 Normal operation of ANF-PR
Figure 4 shows the information flow sequence for normal operation of ANF-PR.
rx
FE1 FE2
r2 r2
r2
CC
CC CC CC
Old Connection Old Connection Old Connection
PRP
req/ind
101
r2 r2
r2
CC CC
New Connection New Connection New Connection
SETUP SETUP SETUP
201
req/ind req/ind req/ind
PRS
req/ind
102
SETUP SETUP SETUP
res/con res/con res/con
PRS
res/con
202
r2 r2
r2
CC
CC
Old Connection
Old Connection Old Connection
RELEASE RELEASE RELEASE
req/ind req/ind req/ind
103
NOTE - For simplicity, basic call information flows Channel_Acknowledge request/indication and
Release response/confirmation are not shown.
Figure 4 - Information flow sequence - Normal operation of ANF-PR

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7.2.3.2 Failure to establish new connection
Figure 5 shows the information flow sequence when establishment of the new connection fails.
rx
FE1 FE2
r2 r2
r2
CC
CC CC
CC
Old Connection
Old Connection Old Connection
PRP
req/ind
101
r2
CC
New Connection
SETUP
201
req/ind
PRS
req/ind
(note)
RELEASE
req/ind
RELEASE
res/con
r2 r2
r2
CC CC
Old Connection Old Connection Old Connection
PRE 203
req/ind
104
NOTE - Because of failure to establish the new connection, the PRS request/indication will not reach
FE1.
Figure 5 - Information flow sequence - Failure to establish new connection
7.3 Functional entity actions
The following FE actions shall occur at the points indicated in the figures of 7.2.3.

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7.3.1 Functional entity actions of FE1
101 On receipt of a request from the ANF-PR user, obtain Rerouting Number and Call
Identity, and include in PRP request/indication to FE2.
102 On receipt of PRS request/indication (in conjunction with basic call Setup
request/indication): correlate new connection with old connection; switch over to the user
information channel of the new connection; terminate the user information channel of the
old connection in a suitable manner (pending its release); stimulate the sending of a basic
call Setup response/confirmation; and return with it a PRS response/confirmation.
NOTE 7
The method of terminating the old connection's user information channel is an
implementation matter. See also annex B.
103 On receipt of an indication from the local CC that the old connection has been released,
indicate successful completion of ANF-PR to the ANF-PR user.
104 On receipt of PRE request/indication, terminate ANF-PR and retain the old connection.
Depending on the reason for failure, indicate to the ANF-PR user whether it is
worthwhile invoking again later.
7.3.2 Functional entity actions of FE2
201 On receipt of PRP request/indication, check that ANF-PR is allowed and stimulate the
establishment of a new connection. In conjunction with basic call SETUP request/-
indication, send PRS request/indication to FE1. Terminate the new connection's user
information channel suitably.
NOTE 8
The method of terminating the new connection's user information channel is an
implementation matter. See also annex B.
202 On receipt of PRS response/confirmation indicating success (in conjunction with basic
call Setup response/confirmation), switch over to the new connection. Disconnect the old
user information channel and initiate release of the old connection.
...