SIST-TS TS 101 878 V1.1.1:2004

SLOVENSKI STANDARD
01-april-2004
Harmonizacija telekomunikacij in internetnega protokola prek omrežij (TIPHON), 3.
izdaja - Definicija zmožnosti storitve - Zmožnosti storitve preprostega klica
Telecommunications and Internet Protocol Harmonization Over Networks (TIPHON)
Release 3; Service Capability Definition; Service Capabilities for a simple call
Ta slovenski standard je istoveten z: TS 101 878 Version 1.1.1
ICS:
33.020 Telekomunikacije na splošno Telecommunications in
general
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

Technical Specification
Telecommunications and Internet Protocol
Harmonization Over Networks (TIPHON) Release 3;
Service Capability Definition;
Service Capabilities for a simple call

2 ETSI TS 101 878 V1.1.1 (2002-02)

Reference
DTS/TIPHON-01009
Keywords
IP, service, VoIP
ETSI
650 Route des Lucioles
F-06921 Sophia Antipolis Cedex - FRANCE

Tel.: +33 4 92 94 42 00  Fax: +33 4 93 65 47 16

Siret N° 348 623 562 00017 - NAF 742 C
Association à but non lucratif enregistrée à la
Sous-Préfecture de Grasse (06) N° 7803/88

Important notice
Individual copies of the present document can be downloaded from:
http://www.etsi.org
The present document may be made available in more than one electronic version or in print. In any case of existing or
perceived difference in contents between such versions, the reference version is the Portable Document Format (PDF).
In case of dispute, the reference shall be the printing on ETSI printers of the PDF version kept on a specific network drive
within ETSI Secretariat.
Users of the present document should be aware that the document may be subject to revision or change of status.
Information on the current status of this and other ETSI documents is available at
http://portal.etsi.org/tb/status/status.asp
If you find errors in the present document, send your comment to:
editor@etsi.fr
Copyright Notification
No part may be reproduced except as authorized by written permission.
The copyright and the foregoing restriction extend to reproduction in all media.

© European Telecommunications Standards Institute 2002.
All rights reserved.
ETSI
3 ETSI TS 101 878 V1.1.1 (2002-02)
Contents
Intellectual Property Rights.5
Foreword.5
Introduction .5
1 Scope.7
2 References.7
3 Definitions and abbreviations.9
3.1 Definitions.9
3.2 Abbreviations.11
4 Services and service capabilities .11
4.1 Introduction.11
4.2 The simple call service application .13
4.3 Impact of unique services on roaming.14
4.4 Interconnection and interoperability.14
4.5 Naming strategy.16
4.6 Naming in TIPHON Release 3.17
5 Registration service capabilities.17
5.1 Terminal transport service registration.17
5.2 User service registration.18
5.3 Public telephony carrier selection.18
5.3.1 Per-call carrier selection .18
5.3.2 Carrier pre-selection.19
6 Call Connectivity service capabilities .20
6.1 Simple call establishment.20
6.2 Calling user identity generation.21
6.3 Calling user identity conveyance.23
6.4 Calling user identity delivery .24
6.5 Call rejection.25
6.6 Number portability.25
6.6.1 Number portability - All call query .26
6.6.2 Number portability - Query on release .26
6.6.3 Number portability - Pivot routing (Dropback) .28
6.7 Emergency calls.29
6.8 Authorized emergency priority calls .29
7 Bearer connectivity service capabilities .30
7.1 Bearer creation.30
7.2 Bearer negotiation.31
7.3 Bearer re-negotiation.31
7.4 QoS bearer support.32
7.5 QoS bearer selection.32
7.6 Media path optimization.33
8 Event reporting service capabilities.34
8.1 Event recording.34
9 Application related service capabilities.35
9.1 Third party authorization.35
9.2 Overlap signalling.36
Annex A (normative): ASN Object Identifiers for service capabilities .37
Annex B (informative): Other capabilities.39
B.1 Introduction.39
ETSI
4 ETSI TS 101 878 V1.1.1 (2002-02)
B.2 Lawful interception access.39
B.3 Service resolution for number translation .39
B.4 Service resolution for destination network identity.40
Annex C (informative): TIPHON functional model.42
C.1 Reference model.42
C.2 Domains.42
C.3 Functional groups.42
C.3.1 Types of functional groups.43
History .44

ETSI
5 ETSI TS 101 878 V1.1.1 (2002-02)
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://webapp.etsi.org/IPR/home.asp).
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 Technical Specification (TS) has been produced by ETSI Project Telecommunications and Internet Protocol
Harmonization Over Networks (TIPHON).
The functions needed to provide a service application and its constituent Service Capabilities may be replicated in a
number of domains that are interconnected to provide, for instance, a call.
Service capabilities are indivisible units of interoperability between TIPHON systems. Using known Service
Capabilities, interconnection agreements can specify the Service Capabilities for which the agreement holds.
Service providers and equipment vendors can add value to service capabilities by enhancing them in their networks and
equipment beyond the functionality defined by the standardized definition without adversely impacting interoperability.
Introduction
The approach being taken to standardization in TIPHON represents a departure from that used in the past for PSTN,
ISDN and GSM. Its aim is to allow much greater scope for competition through innovation in the design of equipment
and services. Its aim is also to provide adequate standardization to facilitate the operation of services across
interconnected networks, even networks that use different technologies. The present document presents the initial core
set of service capabilities envisaged to be required to enable Service Providers to offer services on TIPHON networks
that may safely inter-work with existing PSTN services while enabling more advanced services to be subsequently
developed.
Figure 1 shows the relationship of the present document with other TIPHON release 3 deliverables.
ETSI
6 ETSI TS 101 878 V1.1.1 (2002-02)
TR 101 301 Release 3: Scope & Definition
TR 102 008
Definition of Terms
Transport Plane Service Capabilities
TR 101 311 TS 101 878
Architecture & Reference
TS 101 314
configurations
Protocol
Implementer’s
TS 101 882 TS 101 315
Framework
guide
TS 101 885
TS 101 883 TS 101 884
H.323 profile SIP profile H.248 profile
TS 101 520 TS 101 521 TS 101 522 TS 101 804
H.323 PICS SIP PICS H.248PICS
TS, ATS, PIXIT
Figure 1: Relationship with other TIPHON release 3 documents
• TR 101 311 [2] provides the requirements on the transport plane,
• TS 101 878 (the present document) defines service capabilities that are used in the TIPHON Release 3 for a
simple call,
• TS 101 882 [3] provides the Protocol Framework based on the TIPHON Release 3 architecture to implement the
simple call service capabilities as defined in the present document,
• TS 101 315 [4] is an implementer's guide that shows how to use of the meta-protocol to realise the capabilities as
defined in the persent document,
• TS 101 883 [5] provides the protocol mappings for the ITU-T H-323 profile,
• TS 101 884 [6] provides the protocol mappings for the SIP profile,
• TS 101 885 [7] provides the protocol mappings for the ITU-T H-248 profile,
• TS 101 314 [10] provides the architecture and reference configurations for TIPHON Release 3.
ETSI
7 ETSI TS 101 878 V1.1.1 (2002-02)
1 Scope
The present document forms part of TIPHON Release 3 and defines a set of Service Capabilities for the support of
simple call service applications.
Service Capabilities are indivisible technical functions that are used to support service applications. They are defined
from a technical perspective as technical functions and not from a user's perspective as service elements.
The Service Capabilities and their attributes have been defined so that they are capable of supporting a telephony simple
call service application that is compatible with telephony as standardized in ETSI for PSTN and ISDN.
Subsets of the service capabilities defined here can be selected for implementation in equipment and networks to
support particular service applications.
The service capabilities defined here may also be used for the support of service applications other than simple call.
TR 101 835 [8] provides details of the steps involved in a TIPHON release.
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 and/or edition number or version number) or
non-specific.
• For a specific reference, subsequent revisions do not apply.
• For a non-specific reference, the latest version applies.
[1] ETSI TR 101 877: "Telecommunications and Internet Protocol Harmonization Over Networks
(TIPHON); Requirements Definition Study; Scope and Requirements for a Simple call".
[2] ETSI TR 101 311: "Telecommunications and Internet Protocol Harmonization Over Networks
(TIPHON) Release 3; Service Independent requirements definition; Transport Plane".
[3] ETSI TS 101 882: "Telecommunications and Internet protocol Harmonization Over Networks
(TIPHON) Release 3; Protocol Framework Definition and Interface Requirement Definition;
General (meta-protocol)".
[4] ETSI TS 101 315: "Telecommunications and Internet protocol Harmonization Over Networks
(TIPHON) Release 3; Functional Entities, Information Flow and Reference Point Definitions; For
application of TIPHON functional architecture to inter-domain services".
[5] ETSI TS 101 883: "Telecommunications and Internet protocol Harmonization Over Networks
(TIPHON) Release 3; Technology Mapping; Implementation of TIPHON architecture using
H.323".
[6] ETSI TS 101 884: "Telecommunications and Internet protocol Harmonization Over Networks
(TIPHON) Release 3; Technology Mapping; Implementation of TIPHON architecture using SIP".
[7] ETSI TS 101 885: "Telecommunications and Internet protocol Harmonization Over Networks
(TIPHON) Release 3; Technology Mapping; Implementation of TIPHON architecture using
H.248".
[8] ETSI TR 101 835: "Telecommunications and Internet Protocol Harmonization Over Networks
(TIPHON); Project method definition".
[9] ETSI TR 101 301: "Telecommunications and Internet Protocol Harmonization Over Networks
(TIPHON) Release 3; Release Definition".
ETSI
8 ETSI TS 101 878 V1.1.1 (2002-02)
[10] ETSI TS 101 314: "Telecommunications and Internet Protocol Harmonization Over Networks
(TIPHON) Release 3; Abstract Architecture and Reference Points Definition; Network
Architecture and Reference Points".
[11] ETSI TR 101 326: "Telecommunications and Internet Protocol Harmonization Over Networks
(TIPHON); The procedure for determining IP addresses for routeing packets on interconnected IP
networks that support public telephony".
[12] ETSI TR 101 858: "Telecommunications and Internet Protocol Harmonization Over Networks
(TIPHON); Number portability and its implications for TIPHON networks".
[13] ITU-T Recommendation E.164: "The international public telecommunication numbering plan".
[14] ETSI EN 300 089: "Integrated Services Digital Network (ISDN); Calling Line Identification
Presentation (CLIP) supplementary service; Service description".
[15] ETSI EN 301 798 (V1.1.1): "Services and Protocols for Advanced Networks (SPAN); Anonymous
Call Rejection (ACR) Supplementary Service; Service description".
[16] ETSI TR 102 081 (V1.1.1): "Network Aspects (NA); Number Portability Task Force (NPTF);
Signalling requirements to support number portability".
[17] ETSI TS 101 329-2: "Telecommunications and Internet Protocol Harmonization Over Networks
(TIPHON) Release 3; End-to-end Quality of Service in TIPHON Systems; Part 2: Definition of
Speech Quality of Service (QoS) Classes".
[18] ETSI TS 101 331: "Telecommunications security; Lawful Interception (LI); Requirements of Law
Enforcement Agencies".
[19] ETSI TR 101 750: "Telecommunications and Internet Protocol Harmonization Over Networks
(TIPHON); Requirements Definition Study; Studies into the Impact of lawful interception".
[20] ITU-T Recommendation H.323: "Packet-based multimedia communications systems".
[21] ITU-T Recommendation E.106: "Description of an international emergency preference scheme
(IEPS)".
[22] ITU-T Recommendation F.706: "Service Description for an International Emergency Multimedia
Service".
[23] ETSI TR 102 008: "Telecommunications and Internet Protocol Harmonization Over Networks
(TIPHON) Release 3; Terms and Definitions".
[24] ETSI TS 101 520: "Telecommunications and Internet Protocol Harmonization Over Networks
(TIPHON); Implementation Conformance Statement (ICS) proforma for the support of packet
based multimedia communications systems; Support of ITU-T Recommendation H.323".
[25] ETSI TS 101 521: "Telecommunications and Internet Protocol Harmonization Over Networks
(TIPHON); Protocol Implementation Conformance Statement (PICS) proforma for the support of
call signalling protocols and media stream packetization for packet-based multimedia
communication systems; Support of ITU-T Recommendation H.225.0".
[26] ETSI TS 101 522: "Telecommunications and Internet Protocol Harmonization Over Networks
(TIPHON); Protocol Implementation Conformance Statement (PICS) proforma for the support of
control protocol for multimedia communication; Support of ITU-T Recommendation H.245".
[27] ETSI TS 101 804 (all parts): "Telecommunications and Internet Protocol Harmonization Over
Networks (TIPHON) Release 3; Technology Compliance Specifications".
ETSI
9 ETSI TS 101 878 V1.1.1 (2002-02)
3 Definitions and abbreviations
3.1 Definitions
For the purposes of the present document, the following terms and definitions apply:
administrative domain: collection of physical or functional entities under the control of a single administration
aggregate bearer: logical association of functional entities in an IP telephony application and Transport Network
which creates one or more concurrent end to end media flows and which is not limited to the duration of a single call
aggregate bearer admission control: functional entity that determines whether or not a flow is to be admitted as part
of an established aggregate bearer
aggregate bearer measurement function: functional entity that determines the capacity used and remaining in an
aggregate bearer as a result of measuring the actual media flows after taking into account what flows were requested
bearer: logical association of functional entities in an IP telephony application and Transport Network that creates an
end to end media flow for no longer than the duration of a call
domain: collection of physical or functional entities within an administrative domain that share a consistent set of
policies and common technologies
end-user: entity using the services of an IP telephony Service Provider or Transport Network operator
end-user domain: collection of physical or functional entities under the control of an end-user that share a consistent
set of policies and common technologies
first party (call) clearing: first party to hang up, clears the call
functional entity: entity in a system that performs a specific set of functions
functional group: collection of functional entities within a domain
NOTE: In TIPHON systems functional groups are used to structure the necessary functionality to offer IP
telephony services across domains.
gateway functional group: functional group containing the functionality of a network functional group also the
functionality necessary to connect calls to the SCN
NOTE: Gateway functional groups may be classified as originating or terminating based upon their location
within the topology of a specified call.
home network functional group: functional group which is aware of the service application subscribed to by the end-
user
NOTE: Home network functional groups may be classified as originating or terminating based upon their location
within the topology of a specified call.
information flow: interaction between a communicating pair of functional entities
interface: shared boundary between two communicating systems, devices or equipment
intermediate (transit) network functional group: functional group connecting the serving network functional group
to the home network functional group
NOTE: The intermediate network functional group is only present when the serving network functional group and
the home network functional group are not directly connected.
IP network: packet Transport Network comprising one or more transport domains each employing the IP protocol
IP telephony: any telephony related service that is supported on an IP network
ETSI
10 ETSI TS 101 878 V1.1.1 (2002-02)
IP Telephony Service Provider (IPTSP): Service Provider providing IP telephony services
NOTE: The same business entity may act as both a Transport Network operator and an IP telephony Service
Provider.
network: telecommunications network that provides telecommunications services
network functional group: functional group containing the functionality required to establish a call between two
terminals, a gateway and a terminal, or two gateways
NOTE: Network functional groups may be classified as originating or terminating based upon their location
within the topology of a specified call.
network operator: business entity operating a network
number portability: ability of a user to change Service Provider or location without changing their E.164 number
packet flow/transport flow: stream of packets of the same type identified by common address and port numbers
NOTE: The stream may contain either signalling information or content description together with media
information.
private: indication of availability to a pre-determined set of users e.g. private network, private service
protocol: set of semantics, syntax and procedures which govern the exchange of information across an interface
public: indication of availability to the general public. e.g. public network, public service
reference point: conceptual point at the conjunction of two communicating functional entities
service: set of telecommunication related tasks performed for a customer by a Service Provider and supplied in a
business context
service application: way in which a number of service capabilities are combined to provide a service
service capability: specified set of functionalities that are used to provide a component part of a service
service domain: collection of physical or functional entities offering IP telephony services under the control of an IP
telephony Service Provider which share a consistent set of policies and common technologies
Service Provider: business entity that provides services to its customers on a contractual basis and is responsible for
the services offered
Service Provider identifier: globally unique identifier of a Service Provider (service domain)
serving network functional group: functional group that enables terminal functional groups to connect to an IP
telephony Service Provider
Switched Circuit Network (SCN): telecommunications network, e.g. Public Switched Telephone Network (PSTN),
Integrated Services Digital Network (ISDN), and General System for Mobile communications (GSM), that uses
circuit-switched technologies for the support of voice calls
NOTE: The SCN may be a public network or a private network.
terminal: endpoint within the user equipment on which signalling and media flows originate and/or terminate
terminal functional group: functional group representing all the IP telephony functionality within an end-user's
terminal
NOTE: Terminal functional groups may be classified as originating or terminating based upon their location
within the topology of a specified call.
terminal registration functional group: functional group representing the registration functionality within an end-user
domain
TIPHON compliant system: system that complies with the mandatory requirements identified in the TIPHON
specifications
ETSI
11 ETSI TS 101 878 V1.1.1 (2002-02)
transport domain: collection of transport resources sharing a common set of policies, QoS mechanisms and transport
technologies under the control of a Transport Network operator
Transport Network: collection of transport resources which provide IP transport functionality
Transport Network operator: business entity operating a Transport Network
user identifier: information that enables an end user or access to be uniquely known
user profile: service specific information about a user of a service application
3.2 Abbreviations
For the purposes of the present document, the following abbreviations apply:
ACR Anonymous Call Rejection
ASN.1 Abstract Syntax Notation no. 1
BICC Bearer Independent Call Control
CLI Calling Line Identification
CLIP Calling Line Identification Presentation
E.164 ITU-T Recommendation E.164 [13]
GSM Global System Mobile
H.323 ITU-T Recommendation H.323 [20]
ICANN The Internet Corporation for Assigned Names and Numbers
IP Internet Protocol
ISDN Integrated Services Digital Network
ISUP ISDN User Part
ITU International Telecommunications Union
NFG Network functional group
PSTN Public Switched Telephony Network
QoR Query on Release
RpoA Registration point of Attachment
SCN Switched Circuit Network
SIP Session Initiation Protocol
SpoA Service point of Attachment
SV SerVice
TIPHON Telecommunications and Internet Protocol Harmonization Over Networks
TN Transport Network
ACQ All Call Query
ECS Emergency Calling Service
SP Service Provider
4 Services and service capabilities
4.1 Introduction
In ISDN and GSM, the approach to define services that were fully standardized gave little scope for innovation in the
design of the services. This approach was ideally suited to "service inter-working", which was the main goal of the
"public telephone service" and will be explained later.
The technology and the market are now at a different stage of development. There is:
• a common movement and convergence towards IP as the basic network technology; and
• diversity in the protocols that can be used above the network layer with the prospect that SIP, H.323 and the
various signalling systems from the circuit switched world being used in parallel.
Therefore, there is a need for a methodical approach to inter-working between protocols. The market having reached
relative maturity for simple voice communications is now starting a phase of new service development that is best led
by commercial innovation.
ETSI
12 ETSI TS 101 878 V1.1.1 (2002-02)
TIPHON therefore has different objectives from those of the PSTN/ISDN/GSM and so is taking a different approach
[9].
TIPHON is aiming to standardize modules of technical functionality that can be implemented using different protocols
(technologies). This will enable operators and Service Providers to have their new, innovative and proprietary services
supported across multiple networks because TIPHON provides standard units of functionality that can be referred to in
the necessary interconnection agreements.
TIPHON is NOT aiming to standardize any new service applications.
NOTE 1: The only service application being addressed by TIPHON Release 3 is the simple call service application.
Because TIPHON is taking a new approach, it introduces some new terminology, the main new terms
being "service application" and "service capability" (see clause 3.1).
A service application is the technical description of a part of a service. One or more service applications, together with a
commercial arrangement, form a service offering. From a technical perspective, a service application is capable of being
offered as a service without any technical additions. A service application is described at least in part from the
perspective of the user.
A service capability is a unit of technical functionality that can be mixed-and matched to implement part of a
(non-standardized) service application. It is important to understand that a service capability is defined only as a
technical function from the perspective of network implementation and is not an element of service defined from the
perspective of the user. Also the same service capability may be part of more than one service application (e.g. user
registration or user profile) in one or more service offerings.
Figure 2 illustrates the relationship between services, service applications and service capabilities.
Service
Service Application
Service Capability
Service Capability
Service Capability
Commercial Context
Figure 2: Services and service capabilities
Service Capabilities may be used to build a hierarchy of functionality for service applications. This is illustrated in
figure 3. A base service application (A) uses three standardized service applications. All service applications that use
these three capabilities can interwork at this level of functionality (not shown on the diagram). Additional service
applications are built by the same or different Service Providers by adding additional service capabilities. Where the
same additional service capabilities have been added, e.g. the blue one added by both B and D, then the functionality for
interoperability is enhanced.
ETSI
13 ETSI TS 101 878 V1.1.1 (2002-02)

Base Service Application
A
Extra Service Capabilities Extra Service Capabilities
B C
Interoperability
Extended
Service
IntInteerropeoperraabbiliilittyy
Applications
Extra Service Capabilities
D E
Interoperability
Figure 3: Service application hierarchies
NOTE 2: There will be a need for service level agreements for interconnection to specify the service capabilities
supported by each Service Provider.
The approach taken by TIPHON to describe the behaviour of the service capabilities in Release 3 is elaborated below.
Object identifiers for each of these service capabilities are identified in annex A and functional groups are explained in
annex C.
For each service capability the following aspects are defined:
• Purpose: a short description of the intention of the capability;
• Attributes: relevant parameters that are variable for the purpose of standardization. This includes parameters that
are signalled or set by management processes;
• Normal behaviour: the high-level behaviour description in the normal case; and
• Exceptional behaviour: the high-level behaviour description when the normal case cannot be met e.g. when
faults occur or resources cannot be acquired.
4.2 The simple call service application
The simple call service application is defined so that the elements needed to support some of the standardized public
telephone service that is offered on PSTN/ISDN/GSM are available. The public telephone service can be offered over
new technologies, but the TIPHON simple call service application is less prescriptive and allows the support of
enhancements of simple call that are outside the scope of the services defined for PSTN/ISDN/GSM.
The service capabilities that have been defined and can be used by simple call have been defined so that they provide
the functionality necessary for the support of the public telephone service.
ETSI
14 ETSI TS 101 878 V1.1.1 (2002-02)
4.3 Impact of unique services on roaming
In the TIPHON approach, each Service Provider creates their own service offering. This service offering will consists of
any number of service applications possibly bound by one user name.
In deployments where a user may roam on other networks, the visited network may not understand the particulars of
service application that users wish to use and may even not understand the naming scheme used, and in this case the
visited network will treat signalling and media differently. The visited network will relay all signalling back to the home
domain, but will manage locally the creation of bearers and provide quality control as appropriate.
For some service applications such as public telephony, it may be necessary for visited networks to support some
additional functionality such as emergency calls because this essential service needs to be provided locally since it
requires access to local information and/or local points of connection.
4.4 Interconnection and interoperability
A basic distinction is made between services and transport, resulting in three levels of interconnection:
• Service level interconnection, where the same service is presented by the interconnected networks and enables
the users of the two different Service Providers to communicate with each other;
• Roaming level interconnection, where the service is presented only by the home Service Provider but enables its
users to use their services when roaming on another network;
• Transport level interconnection, which enables a Service Provider to run its service over a transport level
infrastructure provided by different operators.
These are best explained by example.
A Service Provider (SP1) defines and offers a Service (SV1) on a Transport Network (TN1). All customers of SP1 who
subscribe to service SV1 can intercommunicate with each other and access that service from any point on TN1 because
TIPHON defines an on-line registration capability.
The operator of TN1 may decide to use transport level interconnections with other networks to link different part of its
own network. These agreements will need to specify some level of transmission quality in order to support the quality
that TN1 requires. These interconnections will be invisible to the service level, as they all appear to be part of TN1.
Suppose transport provider TN1, with agreement from SP1, implements a roaming level interconnection agreement
with another network TN2. The customers of SP1 can use their service SV1 from anywhere on TN1 or TN2. As more
roaming level interconnection agreements are concluded, customers can access the service from more networks.
However they can only use the service SV1 to communicate with other customers of SP1, and not with customers of
other Service Providers (SP2, SP3 etc) who are based on the other networks TN2, TN3 etc. Roaming level
interconnection therefore extends the accessibility of a service but not the set of other parties that can be communicated
with. This is illustrated in figure 4.
ETSI
15 ETSI TS 101 878 V1.1.1 (2002-02)
SV1 SV2
Customers of SV1 can roam anywhere in TN1 and TN2
but cannot communicate with customers of SV2
TN1 TN2
Roaming level interconnection
Figure 4: Effect of roaming level interconnection
If, however, SP1 concludes service level interconnection with SP2/TN2 for SV1, then the set of customers who can
communicate with each other is increased to include the customers of SP2. Service level interconnection increases the
set of other parties that can be communicated with. The functionality is limited to the common set of service capabilities
between SP1 and SP2. This is illustrated in figure 5.
SV1 SV2
Customers of SV1 and SV2 can roam anywhere in TN1 and TN2
and can communicate with each other
TN1 TN2
Service level interconnection
Figure 5: Effect of service level interconnection
The agreement for service level interconnection will need to specify:
• A common base service application or applications that will be inter-worked;
• Common standardized service capabilities at the service level together with the values of any particular
parameters (e.g. a form of profile);
• Any additional common but non-standardized functionality at the service level;
• A common naming scheme with a coordinated system for allocating names to users;
• A Service Provider identity that the roaming user will use at registration time;
ETSI
16 ETSI TS 101 878 V1.1.1 (2002-02)
• An agreed naming scheme for identifying each network (for routing, it is necessary to determine the home
network name from the called user name);
• The technology (protocols) for implementing the interconnection.
Together with the relevant quality of service values and the commercial arrangements.
The agreement for roaming level interconnection will need to specify:
• Service capabilities needed for the roaming users along with parameters that may be prescribed or signalled
during service usage;
• A Service Provider identity that the roaming user will use at registration time;
• Service applications that are to be resolved locally (such as emergency calls);
• The technology (protocols) for implementing the interconnection.
Together with the relevant quality of service values and the commercial arrangements.
The agreement for transport level interconnection will need to specify:
• Any non-standardized functionality at the transport level that is the subject of innovation;
• Technology (Protocols) e.g. IP or ATM used to implement the inter-domain transport and signalling.
Together with the relevant quality of service values and the commercial arrangements.
There are three types of functional grouping defined in the TIPHON architecture [10]:
• Originating functional group;
• Intermediate (transit) functional group;
• Terminating functional group.
The description of the service capabilities in the present document refer to these functional groupings where they
depend on the type of functional grouping (e.g. for service capability X, the originating functional group shall do Y and
the intermediate functional group shall do Z).
4.5 Naming strategy
The choice of the naming scheme to be used is an important part of the specification of a service because the choice of
naming scheme places an absolute limit on the set of entities that can be communicated with.
Also, any network that provides the service or provides service level interconnection needs to be able to resolve the
names used into addresses using information obtained from registration. For roaming level interconnection, this does
not apply.
Call set-up and some other service capabilities involve names. For call set-up, at least these names have to be resolved
into addresses for routing. This can occur in several stages by networks with service level interconnection but is
performed finally by the terminating Home network. All these networks need to be able to understand the naming
scheme used (for this user). The final resolution needs to use information obtained during the registration process of the
terminating user. A home network will have this information for its own customers as a result of their registration, but
will not have this information for users normally registered with an interconnected network. In order to set up calls to
customers of an interconnected network, a service level interconnection is needed. This must ensure that customers can
be identified by names, allowing the interconnected network to use its own registration information for resolving these
names to addresses.
In contrast, roaming level interconnection only extends the reach of registration and thus the home Service Provider can
still resolve the names of its customers to addresses on the visited networks. Thus roaming level interconnection does
not require the support of the same naming scheme and only requires knowledge of addresses.
ETSI
17 ETSI TS 101
...