ENUM in Austria experienced high expectations initially but saw low usage figures over time. The document discusses Austria's experience with ENUM from its early phases through commercial deployment. Key lessons learned include the chicken and egg problem of needing both ENUM registrations and services to drive adoption, as well as issues around user and provider opt-in, number portability, and international interoperability. The way forward sees benefits of ENUM for routing and interconnection, and believes industry support and IP migration will help promote ENUM in the future.
1. ENUM in Austria
From high expectations to low usage figures. And then?
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.
2. One of my slides from 2001 …
nce ?
v er g e
The Key to Con
EN UM:
ENUM
The Internet
c Switched
ditionalquot; Publi
“Tra
rk (PSTN)
lephone Netwo
Te Best Effort
y
(No) Plug & Pla
Easy to use
Reliable 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
27.01.2009 IIR Interconnection World Forum 2009 Page 2
6. Phases of the Austrian ENUM Story
Warming Forming Storming
Mourning
Norming Performing
27.01.2009 IIR Interconnection World Forum 2009 Page 6
7. 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
27.01.2009 IIR Interconnection World Forum 2009 Page 7
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
27.01.2009 IIR Interconnection World Forum 2009 Page 8
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)
27.01.2009 IIR Interconnection World Forum 2009 Page 9
10. The Legal Framework (I)
New Austrian Telecommunication Law (TKG 2003)
In force since August 20th 2003
Based on the New European Legal Framework
New Numbering Ordinance in Austria
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)
27.01.2009 IIR Interconnection World Forum 2009 Page 10
11. Number Ranges made available for ENUM
Designated for the use with ENUM
Numbers for convergent
A services – (0)780 Gateway to the PSTN required
Usable for VoIP
Location independent fixed
B network numbers - (0)720 Also possible as „Personal Numbers“
numbers directly assigned to end-user
C Private networks - 05
validation via assignment document
Also pre-paid numbers are usable
D Mobile numbers – (0)6
Validation by premium rate SMS
Most common numbers
E Geographic numbers
Validation by postal mail and PIN
[ + (0)800 toll free numbers ]
27.01.2009 IIR Interconnection World Forum 2009 Page 11
12. ENUM-driven Number Range (0)780
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
13. The Generic Gateway
ENUM
Tier 1
Calling
Party A ENUM
Tier 2
Generic
Gateway
Internet
PSTN
Registration
Called
Party B
27.01.2009 IIR Interconnection World Forum 2009 Page 13
14. 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 …
27.01.2009 IIR Interconnection World Forum 2009 Page 14
15. 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).
27.01.2009 IIR Interconnection World Forum 2009 Page 15
16. enum.at - The official Austrian ENUM Registry
http://www.enum.at
27.01.2009 IIR Interconnection World Forum 2009 Page 16
17. IPcom - One of 13 Austrian ENUM Registrars
http://www.my-enum.at/
27.01.2009 IIR Interconnection World Forum 2009 Page 17
18. ENUM Delegations in Austria by Q3/2008
27.01.2009 IIR Interconnection World Forum 2009 Page 18
19. Numbers in ENUM by 26.01.2009
http://crawler.enum.at
27.01.2009 IIR Interconnection World Forum 2009 Page 19
21. 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
Skepticism from providers
1) the value of a telecommunications network is proportional to the square of the number of users of the system (n2)
27.01.2009 IIR Interconnection World Forum 2009 Page 21
22. User ENUM (cont’d)
Weaknesses
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
27.01.2009 IIR Interconnection World Forum 2009 Page 22
23. 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)
27.01.2009 IIR Interconnection World Forum 2009 Page 23
24. 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?
27.01.2009 IIR Interconnection World Forum 2009 Page 24
26. General Benefits of ENUM remain
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 first slide: ENUM – Key to Convergence?)
27.01.2009 IIR Interconnection World Forum 2009 Page 26
27. Benefits once more …
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
27.01.2009 IIR Interconnection World Forum 2009 Page 27
28. A matter of time ...
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
27.01.2009 IIR Interconnection World Forum 2009 Page 28
29. Finally from a regulatory point of view ...
ENUM has been well supported in its infancy
ENUM has gained some attention
ENUM is deployed in some places
ENUM is ready to stand on its own feet
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
27.01.2009 IIR Interconnection World Forum 2009 Page 29
30. ! Thank you.
Kurt Reichinger
Austrian Regulatory Authority for
Telecommunications and Broadcasting
32. 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 )
27.01.2009 IIR Interconnection World Forum 2009 Page 32
33. 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 Web: www.rtr.at
ENUM
27.01.2009 IIR Interconnection World Forum 2009 Page 33
34. 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.
27.01.2009 IIR Interconnection World Forum 2009 Page 34
36. ENUM Domain Name
„Fully qualified E.164 telephone number“
+43 1 58058 306
43158058306
60385085134
6.0.3.8.5.0.8.5.1.3.4
„Fully qualified domain name“
6.0.3.8.5.0.8.5.1.3.4.e164.arpa
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
27.01.2009 IIR Interconnection World Forum 2009 Page 36
37. 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.
27.01.2009 IIR Interconnection World Forum 2009 Page 37