SIST-V ETSI/EG 201 781 V1.1.1:2003
(Main)Intelligent Network (IN) - Lawful interception
Intelligent Network (IN) - Lawful interception
The scope of this ETSI Guide is to cover the standardisation of functions to allow lawful interception of services running in on IN platform. These functions probably need to be defined in the SSP anc SCP, including the information flox between these entities. Alternatives will, however, be investigated. As specific parts of the information flow are confidential, security aspects need to be addressed. Reference documents: ETR 330, ETR 331, ES 201 158.
Inteligentno omrežje (IN) - Zakonito prestrezanje
General Information
Standards Content (Sample)
SLOVENSKI STANDARD
01-november-2003
Inteligentno omrežje (IN) - Zakonito prestrezanje
Intelligent Network (IN) - Lawful interception
Ta slovenski standard je istoveten z: EG 201 781 Version 1.1.1
ICS:
33.040.35 Telefonska omrežja Telephone networks
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
ETSI Guide
Intelligent Networks (IN);
Lawful Interception
2 ETSI EG 201 781 V1.1.1 (2000-07)
Reference
DEG/SPAN-061209
Keywords
IN, security
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All rights reserved.
ETSI
3 ETSI EG 201 781 V1.1.1 (2000-07)
Contents
Intellectual Property Rights.6
Foreword.6
1 Scope .7
2 References .7
3 Definitions and abbreviations.8
3.1 Definitions.8
3.2 Abbreviations .10
4 Introduction .11
5 General Requirements for Lawful Interception.11
5.1 Introduction .11
5.2 General LEA Requirements .11
5.3 Requirement for Network Functions .11
5.4 IN Specific Requirements .11
6 Functional IN architecture.12
6.1 Distributed functional plane model .12
6.1.1 Capability Set 1 (CS-1) distributed functional plane model .13
6.1.2 Capability Set 2 (CS-2) distributed functional plane model .13
6.2 Internetworking .14
6.2.1 Capability Set 1 (CS-1) internetworking .14
6.2.2 Capability Set 2 (CS-2) internetworking .15
7 LI architecture .15
7.1 General .15
7.2 Functions and procedures involved in LI for IN calls .16
7.2.1 LI Data Management .16
7.2.2 LI Data extraction .16
7.2.3 LI Target detection.17
7.2.4 LI CC Delivery function .17
7.2.5 LI IRI Delivery function .17
7.2.6 Mediation Function.17
7.3 Distributed functional model.17
7.3.1 IN functional model.17
7.3.2 Definition of functional entities related to LI of IN services .17
7.3.2.1 LI Management function.17
7.3.2.2 LI Data extraction .18
7.3.2.3 LI Target detection.18
7.3.2.4 LI CC Delivery function .18
7.3.2.5 LI IRI delivery function .18
7.3.3 Interfaces.18
7.3.3.1 Interface data description .18
7.3.3.1.1 LI-CC Delivery Data .18
7.3.3.1.2 LI-IRI Delivery Data .18
7.3.3.1.3 LI Target Data .18
7.3.3.1.4 LI-trigger - Info .18
7.3.3.1.5 LI-Active [optional].19
7.3.3.1.6 CID .19
7.3.3.2 Interface description.19
7.3.3.2.1 Interface It .19
7.3.3.2.2 Interface Ii .19
7.3.3.2.3 Interface Ir .19
7.3.3.2.4 Interface Ic.19
7.3.3.2.5 Interface Ia.20
7.3.3.2.6 Interface I1_c.20
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4 ETSI EG 201 781 V1.1.1 (2000-07)
7.3.3.2.7 Interface I1_d .20
7.3.3.2.8 Interface I1_t .20
8 Security Aspects of LI for IN.20
8.1 Requirements.20
8.2 Solutions.21
Annex A (informative): Lawful Interception Principles for Intelligent Networks .22
A.1 Introduction .22
A.1.1 Background .22
A.2 Intercepted Target Identities.22
A.3 Triggers/Activation of interception.22
A.3.1 Access Based trigger .23
A.3.2 Number Based trigger .23
A.3.3 Service Based trigger.23
A.4 Issues .23
A.4.1 Subscriber controlled input: .24
Annex B (informative): Implementation options for the generic functional model .25
B.1 SCP with no LI related functionality.25
B.1.1 Characteristics .26
B.2 Limited LI functionality in SCP.26
B.2.1 Characteristics .27
B.3 LI functionality in SCP, NO LI related signalling between CCFs .27
B.3.1 Characteristics .28
B.4 LI functionality in SCP, LI related signalling between CCFs.29
B.4.1 Characteristics .29
B.4.2 Limitations .30
B.5 LI functionality in SCP, related signalling between CCFs.30
B.5.1 Characteristics .31
B.6 LI functionality in LI Service Application on SCP.31
B.6.1 Characteristics .32
B.6.2 Limitations .32
B.7 LI functionality in SCP, NO LI related signalling between CCFs .33
B.7.1 Characteristics .34
Annex C (informative): Interface Data Description.35
C.1 Common Data Types.35
C.2 It Interface .37
C.3 Ii Interface .37
C.4 Ia Interface.37
C.5 Ir Interface.37
C.6 Ic Interface.37
C.7 LI data on the SCP-SSP interface.38
C.7.1 LI data over the INAP protocol.38
C.7.2 LI data over a separate communication channel.39
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5 ETSI EG 201 781 V1.1.1 (2000-07)
Annex D (informative): Topics for future work .41
D.1 Mutual legal assistance between LEAs .41
D.2 Interworking with other countries .41
D.3 Interworking with other protocols.41
D.4 CS-3.41
D.5 CS-4.41
D.6 CAMEL.41
History .42
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6 ETSI EG 201 781 V1.1.1 (2000-07)
Intellectual Property Rights
IPRs essential or potentially essential to the present document may have been declared to ETSI. The information
pertaining to these essential IPRs, if any, is publicly available for ETSI members and non-members, and can be found
in ETSI SR 000 314: "Intellectual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified to ETSI in
respect of ETSI standards", which is available from the ETSI Secretariat. Latest updates are available on the ETSI Web
server (http://www.etsi.org/ipr).
Pursuant to the ETSI IPR Policy, no investigation, including IPR searches, has been carried out by ETSI. No guarantee
can be given as to the existence of other IPRs not referenced in ETSI SR 000 314 (or the updates on the ETSI Web
server) which are, or may be, or may become, essential to the present document.
Foreword
This ETSI Guide (EG) has been produced by ETSI Technical Committee Services and Protocols for Advanced
Networks (SPAN).
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7 ETSI EG 201 781 V1.1.1 (2000-07)
1 Scope
The present document lays down architectural requirements for the lawful interception of IN services. Those
requirements shall be fulfilled to allow the Network Operator, an Access Provider or a Service Provider
(NWO/AP/SvP) to implement an interception order from a Law Enforcement Agency (LEA) and to provide the
handover interface to the LEA which is described in other documents. The provision of lawful interception is a
requirement of national law, which is usually mandatory for the operation of any telecommunication service.
The present document specifies the generic flow of information and generic interfaces, which are focussing on IN
capability set CS1and CS2 services. Future services should follow the guidelines where possible.
CS3, CS4 and CAMEL are not examined in this version of the document but may be included in future versions.
The present document does not specify how these generic flows of information and generic interfaces shall be used to
intercept a specific IN service. There will normally be several implementation methods available by using the generic
interfaces. Details for a service, which affects the way interception is already carried out shall be negotiated between the
NWO/AP/SvPs and the responsible regulatory authority on a national basis.
Where applicable, this guide is based on other ETSI standards or ITU-T Recommendations in the area of
telecommunication services. The reader should be familiar with the referenced standards/recommendations, including
the ITU Recommendations, which are endorsed by many of the referenced ETSI standards.
It is not intended to define enhancements of specific interfaces like HI2 and HI3 in the present document. This work
shall be covered by other ETSI documents.
2 References
The following documents contain provisions which, through reference in this text, constitute provisions of the present
document.
• References are either specific (identified by date of publication, edition number, version number, etc.) or
non-specific.
• For a specific reference, subsequent revisions do not apply.
• For a non-specific reference, the latest version applies.
• A non-specific reference to an ETS shall also be taken to refer to later versions published as an EN with the same
number.
[1] ETSI ETR 331: "Definition of user Requirements for lawful interception of telecommunications;
Requirements of the law enforcement agencies".
[2] ETSI ES 201 158: "Telecommunications security; Lawful Interception (LI); Requirements for
network functions".
[3] ETSI ES 201 671: "Telecommunications Security; Handover Interface for Lawful interception of
telecommunications traffic".
[4] ETSI ETR 330: "Guide to the legal and regulatory environment".
[5] ITU-T Recommendation X.881: "Information technology - Remote operations: OSI
realisations - Remote Operations Service Element (ROSE) service definition".
[6] ITU-T Recommendation Q.1204: "Intelligent Network Distributed Functional Plane Architecture".
[7] ITU-T Recommendation Q.1211: "Introduction to Intelligent Network Capability Set 1".
[8] ITU-T Recommendation Q.1221: "Introduction to Intelligent Network Capability Set 2".
[9] ITU-T Recommendation Q.1231: "Introduction to Intelligent Network Capability Set 3".
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8 ETSI EG 201 781 V1.1.1 (2000-07)
[10] ITU-T Recommendation Q.1241: "Introduction to Intelligent Network Capability Set 4".
[11] ITU-T Recommendation Q.1214: "Distributed Functional Plane for Intelligent Network CS-1".
[12] ETSI EN 301 140-5: "Intelligent Network (IN); Intelligent Network Application Protocol (INAP);
Capability Set 2 (CS2); Part 5: Distributed Functional Plane (DFP) [ITU-T Recommendation
Q.1224 (1997) modified]".
[13] ETSI ETR 232: "Security Techniques Advisory Group (STAG); Glossary of security
terminology".
[14] European Union Council Resolution on the Lawful Interception of Telecommunications (17
January 1995).
[15] ETSI ETR 164: "Integrated Services Digital Network (ISDN);Intelligent Network (IN);Interaction
between IN Application Protocol (INAP) and ISDN User Part (ISUP) version 2".
[16] ETSI ETS 300 374-1: "Intelligent Network (IN); Intelligent Network Capability Set 1 (CS1); Core
Intelligent Network Application Protocol (INAP); Part 1: Protocol specification".
[17] ITU-T Recommendation Q.1224: "Distributed functional plane for intelligent network Capability
Set 2".
3 Definitions and abbreviations
3.1 Definitions
For the purposes of the present document, the terms and definitions given in [1], [2] and [3] and the following apply:
accountability: principle whereby individuals are held responsible for the effect of any of their actions that might lead
to a violation
access provider: access provider provides a user of some network with access from the user's terminal to that network
NOTE 1: This definition applies specifically for the present document. In a particular case, the access provider and
network operator may be a common commercial entity.
NOTE 2: The definitions from ETR 331 have been expanded to include reference to an access provider, where
appropriate.
activation/deactivation: procedures for activation, which is the operation of bringing the service into the "ready for
invocation" state, and deactivation, which is the complementary action, are described in this clause. For some services
there may be a specific user procedure to allow activation and deactivation as necessary, whilst for others the service is
permanently activated on provision and thus no procedure is provided (see [5])
availability: avoidance of unacceptable delay in obtaining authorized access to information or IT resources
call: any temporarily switched connection capable of transferring information between two or more users of a
telecommunications system. In this context a user may be a person or a machine
call identifier: number, generated automatically by the internal interception function for each call or call leg of a
intercept subject identity
confidentiality: avoidance of the disclosure of information without the permission of its owner
content of communication: information exchanged between two or more users of a telecommunications service,
excluding intercept related information. This includes information which may, as part of some telecommunications
service, be stored by one user for subsequent retrieval by another
handover interface: physical and logical interface across which the interception measures are requested from network
operator / access provider / service provider, and the results of interception are delivered from a network operator /
access provider / service provider to a law enforcement monitoring facility
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9 ETSI EG 201 781 V1.1.1 (2000-07)
HI1 Information: data received over the HI1 Interface
identity: system-unique tag applied to a user
IN call: call, which involves the IN layer. It may involve a virtual subscriber, but it may also only involve an operator
network function, like Number Portability
IN service: service, which uses IN technology
Integrity: avoidance of the unauthorized modification of information
interception: action (based on the law), performed by an network operator / access provider / service provider, of
making available certain information and providing that information to a law enforcement monitoring facility
NOTE 3: In the present document the term interception is not used to describe the action of observing
communications by a law enforcement agency (see below).
intercept related information: collection of information or data associated with telecommunication services involving
the intercept subject identity, specifically call associated information or data (e.g. unsuccessful call attempts), service
associated information or data (e.g. service profile management by subscriber) and location information
interception Subject: person or persons, specified in a lawful authorization, whose telecommunications are to be
intercepted
internal network interface: network's internal interface between the Internal Intercepting Function and a mediation
device
invocation and operation: these terms describes the action and conditions under which the service is brought into
operation; in the case of a lawful interception this may only be on a particular call. It should be noted that when lawful
interception is activated, it shall be invoked on all calls (Invocation takes place either subsequent to or simultaneously
with activation.). Operation is the procedure which occurs once a service has been invoked. Remark: The definition is
based on [5], but has been adopted for the special application of lawful interception, instead of supplementary services
law enforcement agency: organization authorized by a lawful authorization based on a national law to request
interception measures and to receive the results of telecommunications interceptions
law enforcement monitoring facility: enforcement facility designated as the transmission destination for the results of
interception relating to a particular interception subject
lawful authorization: permission granted to a LEA under certain conditions to intercept specified telecommunications
and requiring co-operation from a network operator / access provider / service provider. Typically this refers to a
warrant or order issued by a lawfully authorized body
lawful interception: see interception
lawful interception identifier: identifier, generated by the law enforcement agency, which relates to a specific lawful
authorization. It is used as an alias for the intercept subject identity
LI list: list with intercept subject identities
LI data: information (e.g. prefix, INAP operation, parameter in some INAP operation etc.) that enables the execution
(start, duration and end) of the intercept warrant in the switching layer. This LI data is to be sent on a call by call basis,
as opposed to only when the intercept period starts and ends
location information: information relating to the geographic, physical or logical location of an identity relating to an
interception subject
mediation device: equipment, which realizes the mediation function
mediation function: mechanism which passes information between a network operator, an access provider or service
provider and a handover interface, and information between the internal network interface and the handover interface
network element: component of the network structure, such as a local exchange, higher order switch or service control
processor
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10 ETSI EG 201 781 V1.1.1 (2000-07)
network operator: operator of a public telecommunications infrastructure which permits the conveyance of signals
between defined network termination points by wire, by microwave, by optical means or by other electromagnetic
means
service provider: natural or legal person providing one or more public telecommunications services whose provision
consists wholly or partly in the transmission and routing of signals on a telecommunications network. A service
provider needs not necessarily run his own network
Service subscriber: natural or legal person who subscribes to a service offered by a service provider
Subscriber Controlled Input: customer control activity, either through the PSTN/ISDN network, or the data
communication network, to the IN layer
target identity: technical identity (e.g. the interception's subject directory number), which uniquely identifies a
intercept subject. One intercept subject may have one or several intercept subject identities
telecommunications: any transfer of signs, signals, writing images, sounds, data or intelligence of any nature
transmitted in whole or in part by a wire, radio, electromagnetic, photoelectronic or photo-optical system
"Virtual" subscriptions: subscription not connected to a physical line card in a switch. Typically an IN service
subscription, e.g. Freephone. The service can be reached through signalling from more than one switch
"Virtual Dial-able" subscriptions: these virtual subscriptions may be designed for incoming calls only. Thus another
party may not call to them. These are called "dialable" subscriptions. Examples are Freephone and Premium Rate
services
"Virtual Non-dial-able" subscriptions: these virtual subscriptions may be designed for outgoing calls only, thus they
may not be called to, by another party. These are called "non-dialable" subscriptions. Examples are Prepaid, Account
and Credit Card Calling services
3.2 Abbreviations
For the purposes of the present document, the following abbreviations apply:
ADMF Administration function
AP Access Provider
BCSM Basic Call State Model
CC Content of Communication
CCAF Call control agent Function
CCF Call Control Function
CID Call Identifier
CPN Calling Party Number
CS-x Capability Set x
CUSF Call Unrelated Service Function (out-channel interaction)
DFP Distributed Functional Plane
HI Handover Interface
HI1 Handover Interface Port 1 (for Administrative Information)
HI2 Handover Interface Port 2 (for Intercept Related Information)
HI3 Handover Interface Port 3 (for Content of Communication)
IAF Intelligent Access Function
IN Intelligent Network
INAP Intelligent Network Application Protocol
iPIWF Internet protocol interworking Function
iPSCF Internet protocol service control Function
IRI Intercept Related Information
LEA Law Enforcement Agency
LEMF Law Enforcement Monitoring Facility
LI Lawful Interception
LIID Lawful Interception Identified – it uniquely identifies a LI-order within all networks
NWO Network Operator
OCN Originally Called Party Number
RDN Redirecting Number
SCEF Service creation environment Function
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11 ETSI EG 201 781 V1.1.1 (2000-07)
SCF Service Control Function
SCP Service Control Program
SCUAF Service Control User Agent Function
SDF Service Data Function
SMAF Service Management Access Function
SMF Service Management Function
SRF Service Resource Function
SS7 Signalling System 7
SSF Service Switching Function
SvP Service Provider
SW Software
TCAP Transaction Capabilities Application Part
UPT Universal Personal telecomunication
4 Introduction
IN technology provides the capability to easily define and implement new IN-services. Although there are general
requirements for LI of telecommunication e.g. [3] and [14], IN specific requirements are nowhere laid down. Since IN
services can be developed by service providers and/or operators it is required to provide means which enable the
developer of an IN service to comply with obligations to provide LI support.
The present document captures requirements, which need to be fulfilled to make LI support of IN services possible.
The fulfilment of these requirements will make it also possible to provide LI support as an IN service.
5 General Requirements for Lawful Interception
5.1 Introduction
This clause presents the Law Enforcement Agency (LEA) requirements, with the LEA as the user, in relation to the
lawful interception of telecommunications. These requirements are subject to national law and international treaties that
should be interpreted in accordance with the applicable national policies. Service, network and access providers may
co-operate to meet LEA requirements. Handover interfaces, to the LEA, shall be configured in accordance with
appropriate ETSI Standards or with national requirements. A handover interface should be in accordance with ES 201
671 [3].
5.2 General LEA Requirements
General requirements for lawful interception of the law enforcement agencies can be found in ETR 331 [1] which is
based on a European Council Resolution [14].
5.3 Requirement for Network Functions
General requirements for lawful interception from the network point of view can be found in ES 201 158 [2].
5.4 IN Specific Requirements
Every IN service shall support LI; exceptions may be agreed between the IN service provider and the relevant national
authorities.
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12 ETSI EG 201 781 V1.1.1 (2000-07)
6 Functional IN architecture
6.1 Distributed functional plane model
The IN distributed functional plane (DFP) architecture has been used to describe the Functional IN architecture.
The IN DFP model is described in ITU-T Recommendation Q.1204 [6]. The diagram consists of functional entities -
representing a unique group of functions in a single location and a subset of the total set of functions required to provide
a service - and relationships - representing a set of information flows between a communicating pair of functional
entities.
Following functional entities have been identified:
• Call control agent function (CCAF) [since CS-1];
• Call control function (CCF)[sinceCS-1];
• Service switching function (SSF)[sinceCS-1];
• Service control function (SCF)[sinceCS-1];
• Service data function (SDF)[sinceCS-1];
• Specialized resource function (SRF)[sinceCS-1];
• Service control user agent function (SCUAF)[sinceCS-2];
• Call unrelated service function (CUSF)[sinceCS-2];
• Intelligent access function (IAF)[sinceCS-2];
• Service creation environment function (SCEF)[sinceCS-1];
• Service management access function (SMAF)[sinceCS-1];
• Service management function (SMF)[sinceCS-1].
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6.1.1 Capability Set 1 (CS-1) distributed functional plane model
Figure 1 identifies the IN DFP model for IN CS-1 as described in Q.1214. This diagram depicts the functional entities
and relationships applicable to IN CS-1.
network
boundary
SMAF
SMF
SCEF
SDF SDF
Management Relationship
IN Service Control
Bearer Connection Control
SCF
Internetworking Relationship
SRF
SSF
CCF CCF
CCAF
Figure 1: IN CS-1 DFP Architecture
6.1.2 Capability Set 2 (CS-2) distributed functional plane model
Figure 2 identifies the IN DFP model for IN CS-2 as described in 3/Q.1224 [17]. This diagram depicts the functional
entities and relationships applicable to IN CS-2.
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14 ETSI EG 201 781 V1.1.1 (2000-07)
network
boundary
to other
SMFs
SMF
SMAF
to other
SDFs
SMF
SCEF
SDF SDF
to other
Management Relationship
SCFs
IN Service Control
Bearer Connection Control
SCF SCF
Internetworking Relationship
IAF
SRF
CUSF SSF
CCF CCF
SCUAF
CCAF
Figure 2: IN CS-2 DFP Architecture
6.2 Internetworking
Internetworking is the process in which several networks (potentially of different types, such as IN-structured, non-IN-
structured, public and private) co-operate to provide a service. The need for internetworking capabilities results from
the fact that the customer may want to access services which span multiple networks.
6.2.1 Capability Set 1 (CS-1) internetworking
IN CS-1 identified the SCF-SDF relationships for internetworking purposes. Neither distributed service logic, nor
distributed service control is supported. Internetwork management interaction is not supported.
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6.2.2 Capability Set 2 (CS-2) internetworking
IN CS-2 identifies the SCF-SCF, SCF-SDF, SCF-IAF, SDF-SDF and SMF-SMF relationships for internetworking
purposes. Distributed service logic, but not distributed service control, is supported. Additionally, internetwork
management interactions and distributed data handling processes are supported.
7 LI architecture
7.1 General
This clause details functions and interfaces, which are required to intercept a call, which invokes an IN service.
General aspects of this clause are contained in ITU-T Recommendation Q.1214 [11].
General LI related interfaces are according to the following model:
HI1
I1_c
ADMF
LEMF
LEMF I1_t
I1_d
LEMF
HI2
Ir
Mediation Delivery
Network
Function * Function 2
using IN
HI3
Ic
Mediation Delivery
Function * Function 3
NOTE: The Mediation Function may be transparent, and may need to be adapted to a regional variant of the HI
interface. The adaptation will be to HI1, HI2 and HI3 as defined in ES 201 671 [3].
Figure 3
The different interfaces are according to the following table:
Symbol Defined in:
I1_c 7.3.3.2.6
I1_d 7.3.3.2.7
I1_t 7.3.3.2.8
Ir 7.3.3.2.3
Ic 7.3.3.2.4
It 7.3.3.2.1
Ii 7.3.3.2.2
The functional model takes this general model and provides details on network internal functions and required
interfaces.
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16 ETSI EG 201 781 V1.1.1 (2000-07)
Generic Functional Plane Model
Network
Boundary
LI-Data
LI Data Ia
Extraction
Management
SMF
Function
It
I1_t
I1_c
I1_d
LI-Target
Detection
Ii
It
SDF SDF
Ir
LI-IRI
LI-Data
Ir
Delivery fct.
IRI-INI
Mediation Extraction
SCF
Function
Ir
SCF
Ii
CC-INI
Ir
SRF
LI-CC
Delivery fct
Ic
SSF
CCF
CCF
CCAF
Figure 4: Lawful Interception for IN Services Functional Plane Model
7.2 Functions and procedures involved in LI for IN calls
The following subclauses provide details for functions and procedures involved in LI for IN.
7.2.1 LI Data Management
The sequence of actions to set up an intercept begins with the delivery of a lawful authorization across the HI1
interface. The information in the lawful authorization needs to be analysed and the relevant data distributed to the LI
functions in the operator's network. This data will typically include the identification of the intercept subject by a
meaningful key, e.g. dialled number (telephone number, credit card number), and the destination address of the
mediation point for the call content and the Intercept related information. The LI Data Management function shall
distribute the relevant information.
7.2.2 LI Data extraction
This function is invoked for every service invocation and whenever the services receives new information (service data,
state change, etc.). The function extracts service specific information, which may be used by the LI Target detection
function to determine, whether a specific call needs to be intercepted. This function is not involved in extracting the
information, which will be reported to the LEA.
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17 ETSI EG 201 781 V1.1.1 (2000-07)
7.2.3 LI Target detection
Once the relevant data is set up in the network it will be necessary to identify any call involving the intercept subject
that satisfies the intercept criteria. Hence there is a need for the service to provide the relevant data on every call to
enable the detection of the intercept subject. This data needs to be analysed and compared against the "meaningful key"
provided by the LI Data Management function. When all criteria are met the SCF or the SSF may arrange for
interception to occur and the Intercept related information may be formatted and delivered to the mediation point. The
LI Target detection function shall identify the need for LI to occur.
This function may also trigger when it receives an indication from another network element that an incoming call has
been identified for interception. This function can then inhibit any further requests for CC interception and forward any
relevant information to the IRI mediation point.
This function may also be involved in non call related activities, which are subject to LI.
7.2.4 LI CC Delivery function
Once the intercept subject and intercept conditions have been identified the actual call content needs to be intercepted
and delivered to the mediation point specified in the I1_c . It will be necessary to identify the identity of the call in
relation to the lawful authorization and the intercept subject as part of the signalling associated with the call. It will also
be necessary to establish a unique identity for the call so that it can be associated with the IRI. The content of the data
sent to the Mediation function should be compatible with the HI3 interface.
7.2.5 LI IRI Delivery function
When the call content intercept is established the required information associated with the call needs to be recovered
from the network. This may include one or all of the following; SSF, CCF, SCF and SDF. This data needs to be
identified as being associated with the intercepted call and delivered to the destination specified by the I1_d. The
content of the data sent to the Mediation function should be compatible with the HI2 interface.
In addition this function shall generate IRI in cases, where call independent data changes are done e.g. changes of
subscriber profile data for UPT service.
7.2.6 Mediation Function
The mediation function is as described in ES 201 671 [3] and will transform the internal data format of the CC-IF and
IRI-IF interfaces into the standard format required at the HI2 and HI3 interfaces to the LEMF. It may be transparent.
7.3 Distributed functional model
LI for IN shall be based on the above shown functional model.
This section provides information on the different i
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