ENUM in Austria
A story of high expectations and low usage figures
Kurt Reichinger
Austrian Regulatory Authority for
Telecommunications and Broadcasting
The opinions expressed in this presentation are the personal view of the
author and do not prejudge decisions of the Austrian regulatory authorities.
19.05.2009 .my ENUM Seminar – Kuala Lumpur

One of my slides from 2001 …
erge n ce ?
ENUM: T he Key to Conv
ENUM
witched The Internet
“Traditional" Public S
(PSTN)
Tele phone Network Best Effort
y
(No) Plug & Pla
Reliable Easy to use Spam
els Viruses
64 kBit/s Chann vices
Multitude of Ser
e
Simple and Saf SIP AORs
High Availability User Accounts
Domain Names
bers
Telephone num
19.05.2009 .my ENUM Seminar – Kuala Lumpur Page 2

… and Usage Figures from 2009
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Agenda
0 What is ENUM? >>
1 The Austrian ENUM Story
2 Lessons Learned
3 Way Forward
Page 4

1 The Austrian ENUM Story
Page 5

Phases of the Austrian ENUM Story
Warming Forming Storming
Norming Performing Mourning
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From Warming to Forming …
August 2001
First public consultation conducted by RTR (i.e. the Austrian Regulatory Authority)
February 2002
(User) ENUM Workshop organized by RTR
Group of interested partners formed Austrian ENUM Trial Platform
May 2002
Delegation request by RTR to RIPE, ITU-TSB for 3.4.e164.arpa
June 2002
3.4.e164.arpa delegated to RTR
ENUM Tier 1 Registry in operation by NIC.AT (i.e. Austrian ccTLD Registry)
September 2002
Austrian ENUM Trial Platform officially established
19.05.2009 .my ENUM Seminar – Kuala Lumpur Page 7

RTR‘s main focus in phase 1/2
Acting as an enabler for innovative technology
§1 Austrian Telecommunications Act mandates promotion of innovation
Inform market players – discuss opportunities and threats
White paper
Public consultation(s)
Public workshop
Prepare landscape for first trials
Providing platform for interested parties
Clarify responsibilities regarding Austrian ENUM Domain
File application for delegation of Austrian ENUM Domain
Persuade the sceptics
19.05.2009 .my ENUM Seminar – Kuala Lumpur Page 8

ENUM Tier 1 Registry
Responsibility for Numbering in Austria (+43)
RTR, i.e. the Regulatory Authority
Responsibility for Austrian ENUM Domain (3.4.e164.arpa)
RTR
Responsibility for ENUM Tier 1 Registry
General RTR
Admin Contact RTR
Tech + Zone Contact Outsourced to nic.at (later to found enum.at)
ENUM trial framework between RTR-GmbH and trial partners
Policy framework for ENUM trial in Austria
Evaluating processes between registry and registrars
Working on (re-)validation processes regarding the right to use number
19.05.2009 .my ENUM Seminar – Kuala Lumpur Page 9

From Storming to Norming …
September 2002
ENUM Tier 2 Name Server in operation by Telekom Austria
November 2002
Policy Framework available
Official start of Austrian ENUM trial
First Live Demo in Atlanta, GA (Fall VON)
December 2002
Ready to invite friendly ENUM subscribers and users
October 2003
1st part of trial completed, 2nd phase (business customers) started
December 2003
Large Scale ENUM and VoIP Pilot started at Vienna University (AT43)
19.05.2009 .my ENUM Seminar – Kuala Lumpur Page 10

RTR‘s main focus in phase 3/4
Ensuring integrity of E.164 Numbering Space and related 3.4.e164.arpa
ENUM Domain Space
Compilation of transparent framework for usage of Austrian ENUM Domain
Definition of requirements regarding identification and validation
Ensuring adherence to the framework
Enabling of maximum competition on ENUM Tier 2 level
ENUM Registrar, ENUM Name Server Provider, ENUM Validation Entity
ENUM Service Provider
Consumer Protection
Ensuring secrecy of telecommunications
Preventing lock-in scenarios
Ensuring end-customer opt-in
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The Legal Framework (I)
New Austrian Telecommunications Law (TKG 2003)
In force since August 20th 2003
Based on the New European Legal Framework
New Austrian Numbering Ordinance
In force since May 12th 2004, Amendment of October 18th 2006
Taking ENUM into account
+43 720 for national portable numbers and VoIP (semi-nomadic)
+43 780 for VoIP and ENUM (nomadic)
Definition of number ranges to be available for ENUM
see next slide
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Number Ranges made available for ENUM
(Used to be) Most common numbers
A Geographic numbers
Validation by postal mail and PIN
Also pre-paid numbers are usable
B Mobile numbers - (0)6
Validation by premium rate SMS
Numbers directly assigned to enduser
C Private networks - 05
Validation via assignment document
Commercially interesting numbers
D Toll free numbers - (0)800
Validation via assignment document
Location independent fixed Usable for VoIP
E network numbers - (0)720 Also possible as „Personal Numbers“
Numbers for convergent Designated for the use with ENUM
F services - (0)780 Gateway to the PSTN required
19.05.2009 .my ENUM Seminar – Kuala Lumpur Page 13

ENUM-driven Number Range (0)780
Number format: +43 780 abcdef (ghi)
Prior delegation of ENUM domain required for assignment of number
Registrar has to provide a Generic Gateway (for this number range)
Cancellation of ENUM domain will (also) relinquish the number
No validation problem as the domain delegation is necessary as the first
step (domains delegated on a first come first served policy)
Decoupling of number range allocation and gateway operator
Any gateway may route the whole number range, just needs to be able to
query ENUM These gateways are called Generic Gateways (GG)
Commercial delegation of domains starting May 2005
19.05.2009 .my ENUM Seminar – Kuala Lumpur

The Generic Gateway
ENUM
Tier 1
Calling
Party A ENUM
Generic Tier 2
Gateway
PSTN Internet
Registration
Called
Party B
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And finally from Performing to Mourning …
October 2003
Decision to start preparation for commercial deployment
May 2004
New Numbering Ordinance defines ENUM-driven number range (780)
August 2004
Contract signed with enum.at concerning a commercial phase
November 2004
End of ENUM trial / Commercial ENUM services made available
May 2005
ENUM enabled number range 780 finally added
April 2006
Addendum to ENUM Agreement allowing Infrastructure ENUM in Austria
Since then
Desperately seeking ENUM users …
19.05.2009 .my ENUM Seminar – Kuala Lumpur Page 16

RTR‘s main focus in phase 5/6
Ensuring smooth transition into commercial phase
Signing of contract with ENUM Tier 1 Registry regarding U-ENUM
Monitoring policy framework requirements
Setting track for Infrastructure ENUM
Work on policy framework
Signing of contract with ENUM Tier 1 Registry regarding I-ENUM
Reducing regulatory involvement
Phasing out of project-oriented work
Establishing of monitoring processes
…
Allowing ENUM to stand on its own feet …
19.05.2009 .my ENUM Seminar – Kuala Lumpur Page 17

The Legal Framework (II)
Contract between RTR and Tier 1 Registry (enum.at)
Signed in August 2004 for a period until the end of 2007 (now ext. to 2009)
Policy framework for ENUM in Austria for 3.4.e164.arpa domain
Basic technical, operational and administrative requirements
Validation guidelines for Registrars
E.g. defining error values depending on the number of delegations with several
procedures occurring when this values are exceeded
Addendum to the existing agreement between RTR and enum.at
Signed in April 2006 allowing the commercial usage of Infrastructure ENUM
Allowing communication service providers to enter numbers of their subscribers
into a separate sub-domain and to add provider-relevant information (e.g. for
routing or billing).
19.05.2009 .my ENUM Seminar – Kuala Lumpur Page 18

Regulatory Involvement over Time
ENUM
Degree of
Trial
regulatory Platform
involvement
I-ENUM
Policy
Framework
U-ENUM
Policy
Framework
Kick-start
process
Phase
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enum.at - The official Austrian ENUM Registry
http://www.enum.at
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IPcom - One of 13 Austrian ENUM Registrars
http://www.my-enum.at/
19.05.2009 .my ENUM Seminar – Kuala Lumpur Page 21

ENUM Delegations in Austria by Q1/2009
Delegations per Number Range
8000
7000
6000
5000
mobile
4000 800
5
3000 720
780
geo
2000
overall
1000
overall
0 geo
5 780
40 6
Q0 10 6
Q0 20 6 720
Q0 30 6
Q0 40 7 5
Q0 10 7
Q0 20 7
Q0 30 7
800
Q0 40
Q0 10
8
8 mobile
Q0 20 8
Q0 30
Q0 40
8
Q0 10
9
Q0
19.05.2009 .my ENUM Seminar – Kuala Lumpur Page 22

Numbers in ENUM by 07.05.2009
http://crawler.enum.at
19.05.2009 .my ENUM Seminar – Kuala Lumpur Page 23

2 Lessons learned
Page 24

User ENUM
General Principle
End-users should opt-in to ENUM with their existing phone numbers on the PSTN
under the domain e164.arpa to provide other end-users with the capability to look up
contact URIs on the Internet the above end-user wants to link to his number
Weaknesses
Most VoIP providers do not provide end-users with SIP URIs to be reached on the
Public Internet (i.e. without generating termination income)
Only the calling party benefits from an ENUM Record of the called party
Chicken and egg problem (with number of ENUM delegations and ENUM services)
and the statistics of Metcalfe’s Law1
Country opt-in regulators involvement slowing process down
End-user opt-in slowing process down further more
General Scepticism of providers
1) the value of a telecommunications network is proportional to the square of the number of users of the system (n2)
19.05.2009 .my ENUM Seminar – Kuala Lumpur Page 25

User ENUM (cont’d)
Weaknesses (cont’d)
National level:
High tariffs to ENUM-driven number range (+43 780)
International level
ENUM-driven number ranges not routed from abroad at all
“Unknown” number range not implemented
“Suspect” number range not implemented
High tariffs to “unknown” number range
19.05.2009 .my ENUM Seminar – Kuala Lumpur Page 26

Infrastructure ENUM
General Principle
Providers should opt-in to ENUM with the telephone numbers of their subscribers
under a defined domain (e.g. i.3.4.e164.arpa for Austria) to provide other providers
with details of their networks‘ ingress points.
Weaknesses
Provider Opt-In
Country Opt-In (again)
Single Tree
What type of tree?
Who is responsible?
How to get all providers on that tree?
How to deal with private ENUM deployments?
Chicken and egg problem (with number of ENUM delegations and ENUM services)
and the statistics of Metcalfe’s Law (again)
19.05.2009 .my ENUM Seminar – Kuala Lumpur Page 27

Private ENUM
General Principle
Providers opt-in to ENUM with the telephone numbers of their subscribers under a
defined domain (e.g. e164.info) to provide fellow providers with details of their
subscribers SIP AoRs.
Also called Operator ENUM, Enterprise ENUM or Carrier ENUM
Current service provider interconnect
Private ENUM in a walled garden scenario
SIP Exchange with restricted access on the Internet
Public tree not in e164.arpa
Weaknesses
Limited reach
No global solution
How to peer with other federations?
19.05.2009 .my ENUM Seminar – Kuala Lumpur Page 28

3 Way forward
Page 29

General Benefits of ENUM remain (1/2)
ENUM is using the DNS
it’s there, it works, it’s global, it scales, it’s reliable, it’s open, anyone can use it…
Saving CAPEX
Enables originating administrative domain to do an All Call Query (ACQ) to
find destination network
Ultimate solution in Number Portability
Provisioning is done only by the destination (recipient) administrative
domain for the E.164 numbers this domain is hosting
Saving OPEX
Enables all multimedia (MM) services for E.164 numbers for all sessions
on IP end-to-end
Enables convergence (remember slide from 2001: ENUM – Key to Convergence?)
19.05.2009 .my ENUM Seminar – Kuala Lumpur Page 30

General Benefits of ENUM remain (2/2)
The major benefits of Infrastructure ENUM for (VoIP) carriers and (VoIP)
service providers is to save costs
Minimal CAPEX for setting up the required infrastructure to provide the
routing data
Minimal OPEX for maintaining routing data
Announce the E.164 numbers you host (in ENUM)
Announce the domains you host (in DNS)
Make bilateral or multilateral peering agreements
Query ENUM and DNS to find any other destination provider
19.05.2009 .my ENUM Seminar – Kuala Lumpur Page 31

Final Considerations (1/2)
ENUM already successfully used
... in Private ENUM deployments (XConnect, e164.info, SPIDER, …)
ENUM still strongly in the focus of standardisation
IETF: WG ENUM, WG SPEERMINT, WG P2PSIP
ETSI/3GPP: ENUM as a building block of the NGN control layer
Future mobile service framework
GSMA: strongly promoting Private ENUM to be used in their IPX framework
Private domain e164enum.net
Not connected to the public DNS
Database possibly linking 2 billion mobile subscriber within the reach of GSMA
Path Finder (GSMA number translation service)
19.05.2009 .my ENUM Seminar – Kuala Lumpur Page 32

Final Considerations (2/2)
ENUM has left its infancy years
Has been well supported, gained attention and is deployed in a couple of places
ENUM now needs more industry support
Standardisation bodies, operators and service providers, service developers
Technological innovation will do its part
Migration to IP-based NGNs will further promote the ENUM case
Industry solutions will emerge
19.05.2009 .my ENUM Seminar – Kuala Lumpur Page 33

! Thank you.
Kurt Reichinger
Austrian Regulatory Authority for
Telecommunications and Broadcasting
Mail: kurt.reichinger[at]rtr.at
Fon: +43 1 58058 306
ENUM: 6.0.3.8.5.0.8.5.1.3.4.e164.arpa
Page 34

3 Backup - What is ENUM?
Page 35

What is ENUM?
Electronic NUmber Mapping: “ … the mapping of Telephone Numbers to
Uniform Resource Identifiers (URIs) using the Domain Name System
(DNS) in the domain e164.arpa …”
ENUM is an IETF standard (RFC 3761) finalized in April 2004 that allows
users and applications to use a telephone number to access a listing of
Internet resources (URI) for that number, such as addresses for IP
telephony, e-mail or Web sites
URIs are used to identify resources on the Internet (e.g. http://www.rtr.at )
19.05.2009 .my ENUM Seminar – Kuala Lumpur Page 36

What is ENUM?
GATEWAY
TEL: +43 1 58058 306 VoIP: 85573@fwd.pulver.com
NUMBER TO URI
FAX: +43 1 58058 9306 E-Mail: kurt.reichinger@rtr.at
MAPPING
MOB: +43 664 1234567 ENUM Web: www.rtr.at
19.05.2009 .my ENUM Seminar – Kuala Lumpur Page 37

Can somebody
ENUM is like an inquiry service help me ?
Who is
+43 1 58058 306 ?
kurt.reichinger@rtr.at
85575@fwd.pulver.com
www.rtr.at
+43 664 1234567
Kurt Reichinger | RTR | Tech. Dept.
kurt.reichinger@rtr.at
85575@fwd.pulver.com
I have some www.rtr.at
information ! +43 664 1234567
Kurt Reichinger | RTR | Tech. Dept.
19.05.2009 .my ENUM Seminar – Kuala Lumpur Page 38

4 Call Scenarios ENUM
+43 1 58058 306 85575@fwd.pulver.com
+43 1 58058 306 85575@fwd.pulver.com
+43 1 2083639
+43 1 2083639 +43 1 2083639
+43 1 2083639 PSTN Internet
19.05.2009 .my ENUM Seminar – Kuala Lumpur Page 39

ENUM Domain Name
+43 1 58058 306 „Fully qualified E.164 telephone number“
43158058306
60385085134
6.0.3.8.5.0.8.5.1.3.4
6.0.3.8.5.0.8.5.1.3.4.e164.arpa „Fully qualified domain name“
As a result of an ENUM Lookup for this domain one gets back the IP-
Address of the server where the data of the user of the corresponding
telephone number are stored. Now this information can be retrieved
19.05.2009 .my ENUM Seminar – Kuala Lumpur Page 40

ENUM NAPTR RRs
ENUM Name Server
>> Agenda
Kurt.reichinger@rtr.at
85575@fwd.pulver.com
www.rtr.at
+43 664 1234567
Kurt Reichinger | RTR | Tech. Dept. NAMING AUTHORITY POINTER
RESOURCE RECORD
$ORIGIN 7.1.4.8.5.0.8.5.1.3.4.e164.arpa.
IN NAPTR 10 10 “u” “E2U+voice” “!ˆ^.*$!sip:85575@fwd.pulver.com!”.
IN NAPTR 10 10 “u” “E2U+email” “!ˆ^.*$!mailto:kurt.reichinger@rtr.at!”.
IN NAPTR 10 20 “u” “E2U+voice” “!ˆ^(.*$)$!tel:+436641234567!”.
usw.
19.05.2009 .my ENUM Seminar – Kuala Lumpur Page 41