SIST-TP TR 101 858 V1.1.1:2004

SLOVENSKI STANDARD
01-april-2004
Harmonizacija telekomunikacij in internetnega protokola prek omrežij (TIPHON) -
Prenosljivost številke in njen vpliv na omrežja TIPHON
Telecommunications and Internet Protocol Harmonization Over Networks (TIPHON);
Number portability and its implications for TIPHON networks
Ta slovenski standard je istoveten z: TR 101 858 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 Report
Telecommunications and Internet Protocols
Harmonization Over Networks (TIPHON);
Number portability and its implications for TIPHON networks

2 ETSI TR 101 858 V1.1.1 (2000-09)
Reference
DTR/TIPHON-04007
Keywords
internet, UPT, network, portability, VoIP
ETSI
650 Route des Lucioles
F-06921 Sophia Antipolis Cedex - FRANCE
Tel.:+33492944200Fax:+33493654716
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://www.etsi.org/tb/status/
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 2000.
All rights reserved.
ETSI
3 ETSI TR 101 858 V1.1.1 (2000-09)
Contents
Intellectual Property Rights.4
Foreword.4
Introduction .4
1 Scope .5
2 References .5
3 Definitions and abbreviations.6
3.1 Definitions.6
3.2 Abbreviations .6
4 Introductory overview .6
4.1 Types of number portability .6
4.2 National strategies .7
4.3 Consumer protection principles.7
4.4 Main applications of number portability .8
4.5 Number portability and personal numbering.8
4.6 Number allocation .9
4.7 Number portability in Europe and the USA .9
4.8 Standardization.10
5 Technical solutions for fixed number portability .10
5.1 Introduction .10
5.2 Which network determines that a number is ported .10
5.3 What the routeing information identifies.11
5.4 How the routeing information is carried.12
5.5 Implementation Techniques used in various countries.12
6 Application to Tiphon .13
6.1 Introduction .13
6.2 Originating network .14
6.3 Transit network .15
6.4 Donor network.16
6.4.1 Onward routeing .17
6.4.2 QoR/Dropback.17
6.4.3 Additional comments.17
6.5 Recipient network.18
7 Conclusions for Tiphon.19
Bibliography.21
History .22
ETSI
4 ETSI TR 101 858 V1.1.1 (2000-09)
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 Technical Report (TR) has been produced by ETSI Project Telecommunications and Internet Protocol
Harmonization Over Networks (TIPHON).
Introduction
The present document provides a general introduction to number portability and identifies various issues that need to be
considered by the designers of TIPHON networks. The present document is co-ordinated with the main ETSI
publications on number portability.
ETSI
5 ETSI TR 101 858 V1.1.1 (2000-09)
1 Scope
The present document gives an introduction to number portability and an overview of the current way in which number
portability is being implemented in various countries. The objective of the present document is to inform the designers
of Tiphon equipment and the implementers of Tiphon networks about:
- the various requirements that they may have to comply with in different countries;
- the implications for equipment and network design.
The present document concentrates on the actual implementations which have been developed rather than the
descriptions given in other standardization documents because:
- the standardization work has been too late to influence many implementations;
- the objective is to help Tiphon networks fit into existing situations.
The present document focuses on the technical implementations. National strategies, responsibilities and charging are
covered only to the extent necessary to outline the context for the technical solutions.
The present document gives most emphasis to number portability of national numbers in fixed networks; as such,
portability of numbers for Global Services and for European Telephony Numbering Space (ETNS) numbers is not
considered.
The present document is complementary to other deliverables on number portability produced by ETSI.
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 TR 101 119 (V1.1.1):"Network Aspects (NA); High level description of number
portability".
[2] ETSI TR 101 122 (V1.1.1): "Network Aspects (NA); Numbering and addressing for Number
Portability".
[3] ETSI TR 101 118 (V1.1.1): "Network Aspects (NA); High level network architecture and
solutions to support number portability".
[4] ETSI TR 101 697 (V1.1.1): "Number Portability Task Force (NPTF); Guidance on choice of
network solutions for service provider portability for geographic and non-geographic numbers".
[5] ETSI EG 201 367 (V1.1.1): "Intelligent Network (IN); Number Portability Task Force (NPTF); IN
and Intelligence Support for Service Provider Number Portability".
[6] ETSI TR 101 698 (V1.1.1): "Number Portability Task Force (NPTF); Administrative support of
service provider portability for geographic and non-geographic numbers".
[7] Directive 97/33/EC of the European Parliament and of the Council of 30 June 1997 on
interconnection in Telecommunications with regard to ensuring universal service and
interoperability through application of the principles of Open Network Provision (ONP) .
ETSI
6 ETSI TR 101 858 V1.1.1 (2000-09)
[8] Directive 98/61/EC of the European Parliament and of the Council of 24 September 1998
amending Directive 97/33/EC with regard to operator number portability and carrier pre-selection.
[9] ITU-T Recommendation Q.931: "ISDN user-network interface layer 3 specification for basic call
control".
[10] ITU-T Recommendation Q.769.1: "Signalling system No. 7 - ISDN user part enhancements for the
support of number portability".
3 Definitions and abbreviations
3.1 Definitions
For the purposes of the present document, the following terms and definitions apply.
donor network: initial network where a number was allocated by the numbering plan administration before ever being
ported.
network routeing number: number that is derived and used by the network to route the call towards a ported number.
operator portability / service provider portability: where a customer changes network/service provider (without
changing location) and keeps the same directory number.
originating network: network where the calling party is connected.
location portability: where a customer changes location (without changing network provider) and keeps the same
directory number.
recipient network: network where a number is located after being ported.
service portability: where a customer changes service (without changing network provider or location) and keeps the
same directory number.
transit network: network between two networks, e.g. . the recipient network and the donor network.
3.2 Abbreviations
For the purposes of the present document, the following abbreviations apply:
ACQ All Call Query
FCC Federal Communications Commission (US)
IN Intelligent Network
ISDN Integrated Services Digital Network
ISUP ISDN User Part
NOA Nature Of Address
PSTN Public Switched Telephone Network
QoR Query on Release
SCN Switched Circuit Networks
SIP Session Initiation Protocol
ToN Type of Number
4 Introductory overview
4.1 Types of number portability
Number portability is the ability for a customer to keep his directory number when changing his telecom network
connection. Three types of number portability are often distinguished:
ETSI
7 ETSI TR 101 858 V1.1.1 (2000-09)
• Operator portability - where a customer changes network provider (without changing location) and keeps the
same directory number.
• Location portability - where a customer changes location (without changing network provider) and keeps the
same directory number.
• Service portability - where a customer changes service (without changing network provider or location) and
keeps the same directory number.
These types may be combined. For example it may be possible to change operator and location while keeping the same
number. In all cases, however, the fundamental objective is to spare customers the considerable inconvenience and/or
cost of a number change, while enabling them to benefit from competition and service upgrades, or to minimize the
disruption of a physical move.
4.2 National strategies
Many countries develop a national strategy on number portability. This strategy consists (ideally) of:
- A statement of the scope and requirements for number portability;
- Routeing rules and rules for the exchange of information;
-Chargingrules;
- A definition of the role of an independent third party e.g. the operator of a national database (if needed);
- Implementation timescales;
and is developed through a process of consultation between the regulator and the operators. In forming the strategy,
choices have to be made between the objectives of promoting competition and of promoting wider user interests,
including benefits from competition.
An important issue is the extent to which the national strategy should define the technical solution to be used. Those
countries that started first to develop number portability focused on the choice of technical solution to be implemented
by all operators. Since then the trend has been to define the strategy by defining the responsibilities for routeing and
charging and allowing the operators freedom to make their own decisions on the technology. This has the advantage
that operators can:
- change their technical solution when it is cost effective to do so,
- use facilities provided by other operators, and
- take full account of possibilities for sharing facilities with other network functions, e.g. sharing IN capabilities.
For example:
- a basic technical strategy would define whether operators should use IN or data decode (re-routeing using
number analysis in switch processors). It would define the charging separately.
- a more flexible strategy would define which operator has responsibility for routeing and what payments may be
made and would allow operators to choose who does the routeing and what technology they use.
4.3 Consumer protection principles
Although competitive considerations often become dominant, the basic motive for introducing number portability is
customer benefit. To ensure continuing consumer protection, most regulators have followed two basic principles:
- Callers should not face unexpected charges. This means that number portability should not reduce the tariff
information that can be deduced easily from the number.
- Customers should retain full choice. This (together with competitive considerations) means that number
portability between operators should be fully reciprocal. In other words, a number once ported should always be
ETSI
8 ETSI TR 101 858 V1.1.1 (2000-09)
able to be returned to its original operator and location. This rule should apply even where a chain of multiple
portings has been undertaken.
Using these principles, regulators around the world have typically restricted the scope of number portability as follows:
- Location portability is typically restricted to the zone in which neither the price of calls nor the geographical
significance of the telephone number is altered (i.e. normally, within a charging area at most).
- Service portability is typically restricted to similar service types. So, for example, fixed number portability
might include the transfer of a number from an ISDN service to a PSTN service; and mobile number portability
might include the transfer of a number from an analogue to a digital service. However, full number portability
between service categories is not normally allowed, as it would remove key tariff, location and service
information from the number. For example, portability between freephone and premium rate services would
destroy the utility of either service.
4.4 Main applications of number portability
In practice there are three main applications for number portability:
• Geographic number portability refers to portability in the fixed geographic networks - the Public Switched
Telephone Network (PSTN) and Integrated Services Digital Network (ISDN). It is primarily concerned at
present with operator portability, but may include limited location portability and service portability. For
example it may be possible to have location portability in the area served by the number block from which the
number has been allocated, or in the whole local charge area. Longer term, with less distance-dependent tariffs,
there may be wider location portability. Fixed number portability may also include an element of service
portability, for example transfers from PSTN to ISDN;
• Mobile number portability refers to the transfer of numbers between mobile operators or service providers. It
may also include service upgrade, for example from analogue to digital service;
• Non-geographic number portability refers to the transfer of numbers between operators or service providers of
fixed non-geographic services. These services are ones where the directory number does not contain any
information about the geographic location of the customer. They include freephone services (typically using the
number prefix 800), shared cost services, and premium rate services.
Table 1 shows the relationships of the types and applications of number portability.
Table 1: Relationship of types and applications of portability
Fixed Mobile Non-geographic
Operator Applicable Applicable Applicable
Location Applicable Not applicable Not applicable
Service Applicable Applicable to service Not applicable
upgrades
As the telecommunications market becomes fully liberalized, there may no longer be a direct relationship between a
network operator and a customer. Instead there may be a multi-layer supply chain, which may feature service providers
and resellers as well as the network operator. In this environment, the full benefits of number portability will only be
obtained if it is applicable to every link in the service provision chain. This may be achieved by:
- placing requirements on service provision, or
- placing requirements on the network operators, together with an insistence that this obligation be reflected in
contracts placed with service providers along the service provision chain.
This choice is influenced by the structure of the national legislation for telecommunications.
4.5 Number portability and personal numbering
Number portability is sometimes confused with the concept of "personal numbering" (a general description that
includes the Universal Personal Telecommunications service). Personal number services enable users to register their
presence at any terminal on any network. Once registered, the customer can make and receive calls to that terminal.
ETSI
9 ETSI TR 101 858 V1.1.1 (2000-09)
Outgoing calls would be billed to the personal number account regardless of originating terminal. There are four key
differences between personal numbers and number portability.
- Personal numbering is a service whereas number portability is a feature of an existing service.
- Personal numbering requires the customer to have a new number in addition to the customer's existing numbers,
enabling use of the personal number across a range of different network numbers without porting these network
numbers. Number portability does not require a number change.
- Personal numbering routes calls to the customer, regardless of the physical network address of the terminal being
used. Calls to a ported number are routed to a given physical network address regardless of the actual location of
the customer.
- Personal numbering uses a temporary association between the personal number and the telephone number of the
terminal to which a call is directed. With number portability, this association is semi-permanent.
Personal numbering is therefore not a substitute for number portability and does not address the competition and user
related issues addressed by number portability. Depending on the method of allocation, personal numbers may be
related to particular providers of personal numbering services, in which case the personal numbers themselves should be
portable.
4.6 Number allocation
The method of number allocation interacts with the solution for number portability. For fixed services, numbers are
currently normally allocated in blocks to each network operator and the operator allocates the individual numbers to the
subscriber. With competing operators, allocations of blocks are normally made within the existing geographical
structure in order to maintain the geographical information in numbers that users have learned.
Allocation through network operators means that the number indicates the operator to which the block allocation was
made, even if the number is ported subsequently. This operator is the initial donor if the number is ported. Because of
the allocations in blocks, the operator is called the "block" operator.
With block allocation, routeing needs only to examine the number to the depth of the block. In the longer term, users
may prefer direct allocations of numbers that are independent of the operators. This implies that there would no longer
be a "block" operator and that more detailed number analysis would be needed, increasing the need for IN. Direct
allocation is already being used for non-geographic services in a few countries, and to improve the efficiency of use
North America is planning allocations at levels below the normal block (called number pooling). The introduction of
individual allocation is quite a major undertaking, requiring:
- a mechanism for allocating numbers to individuals
- a national reference database
- modified billing and support systems
- modified routeing methods, probably by introducing widespread use of IN
The examination below of fixed number portability assumes block allocation that follows the existing geographical
structure.
4.7 Number portability in Europe and the USA
Number portability has been seen in Europe and the USA primarily as a stimulus to competition and the emphasis has
been on operator portability.
The European Commission has addressed number portability in:
- the November 1996 Green Paper on a Numbering Policy
- the Interconnection Directive (97/33/EC [7]) followed by a specific Directive on Number Portability and carrier
selection (98/61/EC [8]), which requires fixed and non-geographic number portability to be implemented by
1 January 2000 so that subscribers may choose to port their numbers. This means that all operators, including
new entrants, have to implement portability.
ETSI
10 ETSI TR 101 858 V1.1.1 (2000-09)
The European Commission in its 1999 Review has recommended the introduction of a requirement for mobile
portability but the outcome will be discussed at some length with member States. Some national regulators are already
requiring mobile number portability, and others are likely to follow this example.
The solutions used for fixed number portability in Europe are quite diverse and are discussed later.
In the USA, a requirement for number portability has been imposed by the FCC as a condition of allowing local carriers
access to the long distance and international markets. There has been a rapid development of a sophisticated solution,
implemented full IN. This solution has been chosen largely as a consequence of the segmentation of the market into
local and long distance carriers. The USA has developed and implemented regional databases to support number
portability and these databases are run by an independent organization.
4.8 Standardization
ETSI has developed several documents on number portability.
TR 101 119: "Network Aspects (NA); High level description of number portability".
TR 101 122: "Network Aspects (NA); Numbering and addressing for Number Portability".
TR 101 118: "Network Aspects (NA); High level network architecture and solutions to support number
portability".
TR 101 697: "Number Portability Task Force (NPTF); Guidance on choice of network solutions for service
provider portability for geographic and non-geographic numbers".
EG 201 367: "Intelligent Network (IN); Number Portability Task Force (NPTF); IN and Intelligence Support for
Service Provider Number Portability".
TR 101 698: "Number Portability Task Force (NPTF); Administrative support of service provider portability for
geographic and non-geographic numbers".
Unfortunately these documents were produced too late to assist most European countries in developing their plans for
number portability.
5 Technical solutions for fixed number portability
5.1 Introduction
The technical solutions to implement number portability can be characterized by:
1) which network determines that a call is to a ported number, and which network derives the routeing information
to route the call towar
...