1. ENUM Overview ENUM Forum Canada
Richard Shockey
IETF ENUM WG Co-Chair
Senior Manager – Strategic Technology Initiatives
NeuStar, Inc.
46000 Center Oak Plaza
Sterling VA USA

2. Agenda
How did we get here?
How does it work?
Where is it going …

3. What is the IETF ? Internet Engineering Task Force
Oversees the standards process for Internet protocols and technologies
Industry driven standards body
No membership whatsoever
Personal participation, anyone can participate
Work is done using mailing lists
Rough consensus and running code (no voting)

4. What is the IETF ? Work is done in Working Groups (i.e. ENUM WG)
WG has a charter, statement of activity, schedule and milestones and a mailing list
WGs can be instantiated and closed (by IESG)
Working Groups exist within an Area (currently 8 areas, i.e. ENUM WG is part of Transport Area)
An area is managed by an Area Director
Area Directors are members of the IESG (Internet Engineering Steering Group)
The IESG and IAB (Internet Architecture Board) is chartered by the Internet Society

5. ENUM in a nutshell RFC 2916 take phone number +1 571 434 5651
turn it into a FQDN
e164.arpa.
ask the DNS
return list of URI’s

6. Step 1 Explanation
Each digit in the FQDN can become a definable and distributed “zone” in DNS terms
Delegation can (biut doesn’t have to) happen at every digit, including at last digit
Zones such as country codes, area codes or primary delegated blocks of numbers can be delegated as well as individual numbers
DNS defines authoritative name servers (NS records) for NAPTR/service resource records

7. The ENUM Delegation Tiers

8. The Response from the DNS
Input:
$ORIGIN e164.arpa
Output: All NAPTR RR will be returned to resolver
In this response the preferred contact method is SIP
ord pr fl service regexp replacement
IN NAPTR "u" “E2U+sip" .
IN NAPTR "u" “E2U+VPIM" "!^.*$!vpimserver1.carrier.net!" .
IN NAPTR "u" “E2U+fax" .
Based on service requirements defined by the enumservice field, translate replacement field into URL and execute as required

9. ENUM WG
RFC 2916 bis is the update of RFC 2916: draft-ietf-enum-rfc2916bis-07.txt
RFC number due at any moment
Main differences are
ENUM is now a DDDS application
enumservice field has changed
enumservices have to be registered with IANA
DNS security mentioned
Clarifications on text

10. Why E.164 Numbers for VoIP?
Addressing is the most important asset in ANY network service!
People know how to use Telephone Numbers
Telephone numbering system (E.164 is stable global and reliable
Billions of devices only use numeric key pads, especially wireless
In the case of Local Number Portability (FCC First Order and Report), MCI has stated that, based on a nationwide Gallup survey, 83 percent of business customers and 80 percent of residential customers would be unlikely to change service providers if they had to change their telephone numbers.
ENUM is perhaps the ultimate in number portability
VoIP and new IP Services (Instant Messaging, Video) can use Real Telephone Numbers!
URIs like have advantages and disadvantages
Biggest problem they cannot be dialed on the PSTN
In fact they cannot be dialed at all …
URI’s and telephone numbers will co-exist for the indefinite future

11. ENUM as glue
An URI (Address of Record) mapped to E.164 ENUM FQDN number allows you:
Reach any destination IP C/UA directly from IP by dialing the full E.164 number as default
support for multiple dialing plans possible including corporate dial plans in a separate tree
see I-D: draft-stastny-enum-numbering-voip-00.txt
In the future, if ENUM and SS7 can be integrated you can reach destinations on IP from the PSTN/ISDN as well
When does a C5 do a ENUM dip?

12. ENUM is a DDDS Application
Dynamic Delegation Discovery System, RFC 3401 through RFC 3405
RFC 3401 is the base document, but you have to read at least RFC 3401 through RFC 3404 to understand DDDS
RFC 3402 specifies the Algorithm of DDDS
RFC 3403 specifies the NAPTR Resource Record

13. Oh BTW ..Its about SIP Internet Engineering Task Force (IETF) protocol
It is the Session Initiation Protocol
Integration of Voice-Text-Video “sessions”
Inventors: M. Handley, H. Schulzrinne, E. Schooler, and J. Rosenberg
Became “Proposed Standard” and RFC 2543 in March 1999 in MMUSIC WG.
Separate SIP WG established in September 1999.
Now new SIPPING (applications) and SIMPLE (presence and instant messaging) WGs using SIP.
RFC2543bis-09 I-D became RFC 3261 in June 2002
Added four new authors: G. Camarillo, A. Johnston, J. Peterson, and R. Sparks.
Entire spec rewritten for clarity, but some new features
Mostly backwards compatible with RFC 2543

14. Simple ENUM/SIP Call Flow SIP RFC 3261
ENUM Global Directory (DNS) Equates to to enable Voice over IP using SIP
3. DNS returns NAPTR record containing SIP URL to Calling Party UA
2. Calling party proxy UAC queries DNS for location of end point
1. The caller simply dials the person’s normal telephone number
4. Calling party UA connects the call

15. ENUM and VoIP as a Hot Potato
ENUM is tightly linked with numbering administrations and therefore within the national regulatory framework
aka Country Code 1 - NANP
Deployment of ENUM is also tightly linked with the deployment of VoIP
Deployment of ENUM involves NRA's and Registries (in Europe primarily the ccTLD's)
Who those registries are a national matter
Surprise Surprise there are lots of Political questions to be answered

16. How do you use ENUM for?
Business: with IP PBX or IP Centrex – core activity
using geographic and/or numbers for networks (opt-in)
linking IP islands together globally via the Internet
Residential: with my geographic number or mobile (opt-in)
secondary line or as primary line (ported out)
Network to Network ...the Private ENUM issue.
Cable Operators
Inter-Intra Enterprise Dial Plan Management
Residential and Business: ENUM-only number ( European Focus )
IP device can be reached from PSTN and IP
calls may be dumped to IP in the originating network using IP specific prefixes like 050 in Japan
Not possible in NANP due to NPA restrictions (non service specific)

17. Public ENUM Vs Operator ENUM
Public ENUM is the administrative policies and procedures surrounding the administration of e164.arpa as defined in RFC 2916
1 to 1 mapping of E.164 number to URI’s
Nation State Control –
Generally speaking Consumer Opt In ( Consumer Control of the NAPTR records)
Operator (Private) ENUM is the use of DNS technology described in RFC 2916 in other domains.
A Managed Service
Service Provider or Enterprise Controlled
Non Visible to the the general Internet user
VPN’s
Access Control to the Data

18. Global Enterprise VoIP Dial Plan
IBM is deploying the biggest VoIP network of any major Fortune 500 company
IBM can unite global VoIP dialing plans across existing VPN and Intranet Links on diverse vendor Platforms
ENUM unites them through common administration and access plan
               
Wireless calls represent a significant and growing portion of total bill
Worker mobility increasing overall telecommunications cost
PDA proliferation will increase the need and use of corporate messaging
ENUM
Public or
Internal

19. MSO Market : Optimal Service Routing
MSO can now optimize VoIP call termination strategies by routing calls directly from one operator to another –ENUM acts a element in a overall Least Cost Routing Strategy
Essentially “Friends and Family” dialing plans among MSO’s
Wireless calls represent a significant and growing portion of total bill
Worker mobility increasing overall telecommunications cost
PDA proliferation will increase the need and use of corporate messaging
ENUM
e164mso.net

20. (Very short) ENUM History
IETF ENUM WG formed
Sept – IETF ENUM WG – RFC2916
2001 – Various Workshops (ITU-T, Europe, US, Asia, …)
2002 – ITU-T Interim Procedures (IAB, RIPE-NCC) – ITU-T generic TLD Investigation – ETSI TS "ENUM Administration in Europe"
2003 – ETSI TS "Minimum Requirements for Interoperability of European ENUM Trials" – IETF various enumservices on standards track – IETF RFC2916bis WGLC
2004 – Planned: – IETF new ENUM RFC, IANA registered enumservices – ITU-T final decision on ENUM domain – ETSI ENUM Workshop (Feb 2004) and Plugtest

21. (Very short) ENUM Trial History
2002 – US ENUM Forum – Trial Platforms in AT, UK, SE, DE, CN, N*… – Austrian ENUM Trial in operation (Sept. 2002)
2003 – Various national and international ENUM Trials using different scenarios and numbering resources and using different ENUM-enabled products – National and international demos and presentations (IETF, ITU-T, VON, ICANN, …) – SIP communities start using ENUM (FWD, Sipphone, iptel, at43, …) – Pre-commercial deployment starts
2004 – ENUM ready for production and deployment (at least in some countries)

22. The IAB – ITU Agreements
Core Principal – Nation-State control of the national portions of the e164.arpa tree.
[RFC3026] Blaine, R. "Liaison to IETF/ISOC on ENUM" RFC 3026, January 2001
[RFC 3245] Klensin, J. Editor "The History and Context of Telephone Number Mapping (ENUM) Operational Decisions:  Informational Documents Contributed to ITU-T Study Group 2  (SG2)", RFC 3245, March 2000
Interim Procedures for the delegation of E.164 Shared Country Codes for Networks and Groups of Countries; 

23. Large Scale IPC Trial at43
Large Scale Trial on IP Communications using ENUM
University of Vienna ~ Students
re-use of existing student account credentials via RADIUS
iptel.org SIP Express Router as SIP proxy with call routing, ENUM processing, PSTN interworking
some functions based on Asterisk open-source IP-PBX:
voic , conference bridge, IVR,
PSTN Connection: CISCO 5300 PSTN/ISDN Gateway with PRA
Various Soft- and Hard-phones, WiFi-Phones, …
IP Connection to other universities, communities and "IP-PBX"
Applications: Crash test for VoIP, Chat, IM, Presence, SMS, use of SIM-Cards…
IP calls free, PSTN->IP calls by caller; IP->PSTN with call-by-call accounting
Naming, Numbering and Addressing with ENUM
Base:
Austrian number for private networks: nnnnnn
global UPT number: nnnnnn
ORIGIN e164.arpa.
* NAPTR "u" "E2U+sip" .

24. DNS Technology as a replacement for SS7
ENUM/DNS and or SIP can provide a more sophisticated, less expensive and easier to deploy Number Translation Services for service providers.
The natural evolution of NextGen telephony signaling systems
SCP costs 1 Million Dollars + PRI’s + per dip charges
DNS Box 25 K maximum BIND9
SS7 signaling is complicated, expensive and disruptive in an all IP architecture
Number Portability- Geographic number to routing number mapping (NP dip)
It’s there
It works… It’s global… It scales… It’s open…

25. Public ENUM Status - What about the US?
US DOMESTIC POLICY – August 13, 2003
United States Government reiterates its support for RFC 2916 and endorses moving forward with ENUM based on the concept of a Industry Managed LLC
LLC is forming NOW !
Similar to Number Portability Structure
United States ENUM Forum - Created by industry to develop policy and steps to Implement ENUM in the United States
Participants include WCOM, ATT, Sprint, SBC, Verizon, NeuStar, Cox , C&W, Cisco, Telcordia

26. ENUM Global Status – 23 Active National Trials
EUROPE
UK National Trials Well Underway 2003
Austrian National ENUM trials have begun with AT-NIC
Jointly working on ITU-UPT code as well
Sweden running since Dec
ITU ENUM web pages

27. ENUM Global Status – National Forums
JAPAN  
Poland
Korea
The Netherlands, Germany, Brazil, China
Approved ENUM Delegation list
ETSI Plugfest

28. Lessons learnt in the ENUM Trials
ENUM technology works,
Most problems solved, but shift in focus for the business models.
The original business model of ENUM for residential subscribers with opt-in for existing numbers has problems:
Potentially it's only a second line service
911 issues
privacy problems with multiple services ( spam)
Validation and re-validation of the number holder problem
How to enable Metcalfe's Law?
The usefulness, or utility, of a network equals the square of the number of users

29. IETF Work Today Privacy Security Operational Experience
servicefield IANA registration
SIP
H.323
Presence
FAX – T.30 and Internet Fax
VPIM
web - msg

30. Privacy and Security issue
What is ENUM
Calling party control –
Global Directory Service
List all available URI for all possible services ?
Called Party control - IMHO the answer
Minimal Routing Data Base
SIP AOR only
Let SIP do the dirty work

31. Security / Authentication issues
What about DNSSEC
Its not ready yet. Period.
Who can register the TN and why?
Punt – It’s a national issue
How do you determine if the ENUM registrant has valid rights to the number?

32. IETF ENUM WG TBD Provisioning protocols the ENUM system WHOIS ?
Tier 1 Tier 2 interactions (SOAP ?)
XML object based on PROVREG work ?
WHOIS ?
Strong technical reasons for wanting a WHOIS like service here
CRISP (aka not port 43)?
The IRIS protocol ?

33. IRIS
Developed in IETF to provide capability sets existing in telecom Intelligent Network environment
Text based protocol designed to allow registries of Internet resources
to express query and result types specific to their needs
while providing a framework for authentication, structured data, entity references and search continuations
Encompasses the following
a decentralized system using DNS hierarchies where possible for location
built upon standard Internet building blocks
does not impose any informational trees or matrices
may be used with multiple application transports, including BEEP

34. IRIS Features XML based Internationalization
Localization of data tags and content
Identifying contact equivalences
Support of Internationalized Domain Names
Unified Service
Structured queries and results
Distinction
Authentication – the process used to verify the identity of a user
Authorization – the access policies applied to a user based on authentication

35. Questions
Contact, not Content, is King
Douglas Rushkoff