ENUM
International Status onStandardization and Deployment

Tokyo, December 8th, 2003

Richard STASTNY
ÖFEG/TELEKOM AUSTRIA, Postbox 147, 1103-Vienna
enum:+43 664 420 4100
E-Mail: richard.stastny@oefeg.atrichard@stastny.com

ENUM and VoIP as a Trigger¾ ENUM is tightly linked with numbering and therefore
with the regulatory framework¾ Deployment of ENUM is also tightly linked with thedeployment of VoIP
¾ Deployment of VoIP causes a direct conflict between
Telco's and ISP's¾ Deployment of ENUM involves NRA's and Registries(in Europe primarily the ccTLD's)¾ ENUM and VoIP therefore causes a lot of questions andissues to surface.

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Areas of Conflict
National Regulatory Authorities(New)
Telecommunication
Law

Numbering(De)regulation

ENUM and VoIP

Telco'sPrivacy Law
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ISP's andother SP

ccTLD's(Registries)
Consumers

Consumer andPrivacy
protection
3Warm-up:
The ENUM Problem Statement¾ How do you find a service on the Internet?
¾ Also from the PSTN?

¾ How do you find “islands of connectivity” acrossdomain boundaries?
¾ Why not use phone numbers?

?
VoiceVideo
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ENUM in a nutshell¾ take phone number+43 1 979 33 21¾ turn it into a FQDN

1.2.3.3.9.7.9.1.3.4.e164.arpa.

¾ ask the DNS¾ return list of URI’s

mailto:richard@stastny.com
sip:richard@iphone.at

Richard Stastny

5How does ENUM work ?
Telephone Number (TN): +43 1 979 33 21 translates to:
1.2.3.3.9.7.9.1.3.4.e164.arpa
Tier 1 resolution to NS of authority ( pointer only)
1.2.3.3.9.7.9.1.3.4.e164.arpa. IN NS ns1.iphone.atTier 2 resolution to NAPTR record and SIP URL controlled at the end office
IN NAPTR 10

10 "u" “E2U+sip“ !^.*$!SIP:richard@iphone.at“!

set up callRichard Stastny

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(Very short) ENUM History¾ Sept. 2000 – IETF ENUM WG – RFC2916¾ 2001 – Various Workshops (ITU-T, Europe, US, Asia, …)¾ 2002 – ITU-T Interim Procedures (IAB, RIPE-NCC)– ITU-T generic TLD Investigation– ETSI TS 102 051 "ENUM Administration in Europe"¾ 2003 – ETSI TS 102 172 "Minimum Requirements forInteroperability of European ENUM Trials"– IETF various enumservices on standards track– IETF RFC2916bis WGLC
¾ 2004 – Planned:– IETF new RFC, IANA registered enumservices– ITU-T final decision on ENUM domain– ETSI ENUM Interop
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(Very short) ENUM Trial History¾ 2002 – US ENUM Forum– Trial Platforms in AT, UK, SE, DE, CN, …
– Austrian ENUM Trial in operation (Sept. 2002)¾ 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 starts¾ 2004 – ENUM ready for production and deployment
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ENUM Delegations
Delegations in e164.arpa as of 16. November 2003¾¾¾¾¾¾¾¾¾¾¾¾¾¾¾

31 Netherlands
33 France
358 Finland
36 Hungary
374 Armenia
40 Romania
41 Switzerland
420 Czech
421 Slovakia
423 Liechtenstein
43 Austria
44 UK46 Sweden
48 Poland
49 Germany¾¾¾¾¾¾¾55 Brazil
86 China
246 Diego Garcia
247 Ascension
290 Saint Helena
971 UAE
87810 VISIONng UPT

http://www.ripe.net/enum/request-archives/

Richard Stastny9Lessons learnt in the ENUM Trials¾ Basic issues solved¾ ENUM technology works,¾ ENUM policy and administration: most problems solved,¾ but shift in focus for the business models.

¾ The original business model of ENUM for residential
subscribers with opt-in for existing numbers has problems:¾ second line service,¾ privacy problems with multiple services (e-mail spam)¾ Validation and re-validation problem, …

¾ but the major problem is: How to overcome Metcalfe's Law?
¾ The usefulness, or utility, of a network equals the square of thenumber of users¾ so new approaches are needed.
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10New approaches to ENUM needed¾ New approaches for IP Communications:¾ ENUM for IP-based private networks ("PBX") with direct dial in¾ Numbers "ported" to IP-based networks (using ENUM for routing)¾ non-geographic number ranges for IP Communications, using ENUM

¾ and then the re-launch of the original ENUM model
starting with teleworkers and road warriors to overcome
Metcalfe's Law¾ Note: IP Communications is not IP Telephony¾ it is VoIP PLUS
¾ Instant Messaging, Presence, Video, Chat, SMS, and, …

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Scenarios for IP Communications¾

The following end-to-end scenarios exist:
1. PSTN/ISDN via IP to PSTN/ISDN¾ good ol' voice bypass, IP trunking, not discussed here
2. IP Communications to IP Communications¾ e.g. hotmail, aol, FWD, sipphone, skype, Telio, …
¾ most including IM, presence, chat, etc.
3. VoIP to PSTN/ISDN¾ e.g. Vonage, Telio, …
4. PSTN/ISDN to VoIP
¾ e.g. Vonage, libretel with 2-stage dialing¾¾

How can the last three scenarios be merged?
What are the impacts of this merger on naming, addressing andnumbering?

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PSTN via IP to PSTN
By-Pass

VoIP
circuit-switched

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IP Communications to IP C.

VoIP
circuit-switched

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IP Communication to IP C.
¾ Naming and Addressing is done by Internet means:¾ usage of IP addresses, URIs and alphanumeric UserIDs¾ if you stay within an Administrative Domain (AD),you use a name (UserID) e.g. richard, marc or frank¾ if you access another AD, you use an URI (Address-of-Record)e.g. richard@aol.com¾ SIP Servers translate URIs to Contact Addresses and the
DNS translate these finally to IP addresses¾ The problem:¾ you soon run out of UserIDs like richard, marc and frankRichard Stastny

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IP C. to PSTN/ISDN

VoIP
circuit-switched

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IP C. to PSTN/ISDN¾ This is easy
¾ Provided you have an outbound VoIP/PSTN gateway¾ you just enter a phone number¾ either in a mutually agreed dialing plan or¾ in the international format +4317978032¾ The PSTN is doing the rest
¾ The problem:¾ The call may not be routed as long as possible on the Internet,
incurring long distance charges¾ If the call finally terminates on the Internet, so you may also nothave an optimal routing (again cost, but more important: QoS)

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PSTN/ISDN to IPVoIP?
circuit-switched

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PSTN/ISDN to IP¾ This is a problem¾ 2-stage dialing is not very elegant¾ Internet names and addresses are not recognized by thePSTN/ISDN¾ So you need a phone number attached to an Internet Name (AoR)¾ The phone number needs to be recognized by thePSTN/ISDN to be routed to a VoIP Gateway¾ The phone number needs to be translated to an Internet
name (URI – AoR) e.g. with ENUM

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Interlude¾ What happened in the meantime in the administrative domains featuring
UserIDs like richard, marc and frank?
¾ The second and all other Richards got e.g. RichS, SRich and Rich1234¾ in addition, IP phones, "ATAs" and "WiSIP" phones got popular featuring
numeric keypads¾ so numeric UserIDs appeared: e.g. 8781@iptel.org, 16421@fwd.pulver.com¾ this "phone" numbers can be dialed directly (like private numbers)¾ Note also: private networks (PBX) migrating to IP use numeric UserIDs as aliases
for user convenience in any case

¾ What about dialing the host part iptel.org on IP phones?
¾ Surprise, suprise, cross trunking as used in private networks was re-invented¾ you now dial e.g. **478 8781 to reach 8781@iptel.org from FWD¾ The problem:¾ more then 10 to 20 cross connections in one domain are not feasible¾ so a global solution is needed

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The following solutions havebeen proposed:
1. Standardize (centrally manage) the prefixesor2. Create a new numbering and dialing plan for IPCommunicationsor
3. Use an existing resource = E.164¾

Since this is the way all PBXs migrating to IP will
(and have to) go anyway¾ The proposal is to implement 3.:¾¾¾obtain an E.164 number range(stub number+DDI range)
allocate DDI "extensions" as userids
export the fully qualified numbers in ENUM

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ENUM as glue
¾ An URI (AoR) entered in an ENUM domain related to an
E.164 number allows you:
¾ to reach any destination on IP from the PSTN/ISDN¾ requirements on the PSTN/ISDN see next slide¾ to reach any destination on IP directly from IP¾ by dialing the full E.164 number as default¾ dialing local numbers and cross connections is still possible¾ if a proper numbering and dialing plan is used
¾ see I-D: draft-stastny-enum-numbering-voip-00.txt¾ and to reach any destination existing only on the PSTN
¾ but only calls to numbers not found in ENUM are routed via thePSTN

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So which E.164 Numbers to use?
¾ National Geographic Numbers¾ National Non-geo Numbers for Private Networks¾ National Non-geo Mobile and Personal Numbers¾ National Non-geo Numbers for IP Telephony¾ National Non-geo Numbers for ENUM

¾ Global Personal (Mobile) Numbers (87810 UPT)

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What is required on the PSTN/ISDN?
1. Numbers both on the PSTN/ISDN and in ENUM (opt-in)¾ Calls originating on IP are routed directly on IP¾ Calls originating on the PSTN are routed and terminated on thePSTN

2. Numbers ported out (locally) to VoIP providers¾ Calls originating on IP are routed directly on IP¾ Calls originating on the PSTN are routed on the PSTN andterminated on IP

3. Numbers routed directly to IP via ENUM¾¾¾¾

"Personal Mobile Number" ranges are assigned for this purposeIf significant enough (max 7 digits), they may be recognized early
and routed to the nearest VoIP ENUM-enable gateway
e.g. +87810, +43723, …

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VISIONng, ENUM and UPT +87810¾ The VISIONng Assoc. was founded in 2001
¾ The mission of VISIONng is to provide a framework for thedeployment of worldwide inter-domain and multi-vendor IP
Communication Services based on international standards.
¾ ITU-T has assigned a part of the country code for UPT to VISIONngfor deployment of an Universal Personal Telecommunication Service:+878 10¾ In May 2002 VISIONng requested an ENUM delegation from RIPE NCC
for trial purposes and got approval from ITU-TSB¾ This VISIONng ENUM Trial was implemented in parallel to theAustrian ENUM Trial within +43¾ In October 2003 VISIONng requested a permanent delegation ine164.arpa from ITU-T and got approval from ITU-T SG2.
¾ VISIONng is planning commercial deployment in 2004.

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Evolution Roadmap by SBC

VoIP
ENUM-enabled
generic GW

circuit-switchedcalls traverse their originating network as
far as possible, then hop off as needed.
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What is required on IP?
¾ ENUM enabled VoIP Gateways (exist)¾ ENUM enabled IP-PBX (exist)¾ ENUM enabled SIP proxies and H.323 gatekeeper (exist)¾ and/or¾ ENUM enabled IP phones and soft clients (exist)¾ Number ranges for residential users (under discussion)¾ Number ranges for corporate users (exist partially)¾ see next slide for the options

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Options for corporate users¾ Assumptions:¾ the company has already an E.164 number, a private numbering plan and amapping of this private numbering plan to the E.164 number with DDI¾ The company migrates to IP Communications, connects to the Internet, butkeeps the PSTN/ISDN connection¾ Step1: Opt-in in ENUM with existing number¾ e.g. ÖFEG +43179780-32 (2 digit DDI)
¾ calls from IP use ENUM, calls from PSTN use PSTN access¾ Step2: Use in addition an ENUM-enabled number¾ e.g. ÖFEG +8781063334281-32 (2-digit DDI) or +437802345-32¾ calls to this number from the PSTN are routed to IP directly¾ Step3: Port out the geographic number to IP¾ dump the PSTN access, use common VoIP gateway from provider¾ calls from IP may use any number, calls from the PSTN may prefer +87810
but may still use +43179780-32

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Call flows+878106333428 32+43179780 32
ENUM

32@iphone.at
32@iphone.at* GK oder SIP ServerGK

32@iphone.at

InternetGW

GW

PBX

32+8781063334281 32
TDM

TDM

TDM+43179780 32

Richard Stastny

29+43179780

Large Scale IPC Trial at43¾ Large Scale Trial on IP Communications using ENUM
¾ University of Vienna ~100.000 Students¾ re-use of existing student account credentials via RADIUS¾ iptel.org SIP Express Router as SIP proxy with call routing, ENUM processing,PSTN interworking¾ some functions based on Asterisk open-source IP-PBX:¾ voice-mail, conference bridge, IVR,
¾ PSTN Connection: CISCO 5300 PSTN/ISDN Gateway with PRA¾ Various Soft- and Hard-phones, WiFi-Phones, …
¾ IP Connection to other universities, communities and "IP-PBX"¾ Applications: Crash test for VoIP, Chat, IM, Presence, SMS, use of SIM-Cards…

¾ IP calls free, PSTN->IP calls by caller; IP->PSTN with call-by-call accounting¾ Naming, Numbering and Addressing with ENUM
¾ Base:¾ Austrian number for private networks:¾ global UPT number:

sip:<student-id>@sip.univie.ac.at+43 59966 nnnnnn+87810 2843 nnnnnn

ORIGIN 6.6.9.9.5.3.4.e164.arpa.
*
NAPTR 100 10 "u" "E2U+sip" "!^¥¥+4359966(.*)$!sip:¥¥1@sip.univie.ac.at!" .

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The End
Thank you foryour attention

Contact (not Content) is King

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