Japan Registry Service

ENUM Tutorial
APTLD Technical Workshop
22 Nov 2003
Yoshiro YONEYA <yone@jprs.co.jp>

Copyright © 2003 JPRSJapan Registry ServiceOverview• Background• ENUM Standards• ENUM Structure• ENUM Operation• ENUM activities in Japan

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Japan Registry ServiceBackground

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What is ENUM?
• ENUM is a mechanism for mapping telephone(E.164) number to Internet resource address(es).
• Internet resource address(es) are specified asURI(s).
• Mapping is performed by DNS lookup.
• End users (Applications) can select URI according
to their preference.
• Standardization by cooperation of IETF and ITUT.
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Telephone and Internet inter-connection• Glowing demand for using IP (or Internet)
telephone.
– Deployment of Broad Band Internet access.
– Cost saving.

• Digits only identifier for Internet resources.
– For the legacy (telephone) interface.
– Telephone number is global unique.

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Further possibilities• End users view:– Unifications of multiple identifiers into one E.164
number.
• Tel#, Fax#, Email address, Web address, etc.

– Increases chance to connect to callee.
• Can be fall back to another URI(s) if line is busy.

• Operators view:– Inter-routing between IP phone carriers.

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Japan Registry ServiceENUM Standards

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E.164 number and DNS
RFC2916• Published on Sep, 2000.
• Defines how to map E.164 number to DNSNAPTR resource record.
• Designates “e164.arpa” for ENUM infrastructure
in DNS.
• RFC2916 is going to be updated.
– Working draft is so called RFC2916bis.
– Re-definition as DDDS (RFC3501-04) application.
– And clarification of specifications.
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E.164 number structure• Standardized at ITU.
• Format– Begin with ‘+’– Followed by country code
– Followed by domestic telephone number• Remove prefix 0 if necessary.

– Consists from 10-15 digits.

• Ex (In case of Japan)– Domestic:– E.164:
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03-5297-2571+81-3-5297-2571
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E.164 to domain name conversion
1.

Check if E.164 is complete.
•2.

Remove all non-digit except for leading ‘+’.
••3.

8.1.3.5.2.9.7.2.5.7.1

Reverse the order of the digits.
•6.

81352972571

Put dots (“.”) between each digit.
•5.

+81352972571
This form is remained as AUS (Application Unique String) for applying
regular expression in NAPTR.

Remove leading ‘+’.
•4.

Ex. +81-3-5297-2571

1.7.5.2.7.9.2.5.3.1.8

Append the string “.e164.arpa” to the end.
•1.7.5.2.7.9.2.5.3.1.8.e164.arpa

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Japan Registry ServiceStructure of NAPTR RR• ENUM defines “E2U” for NAPTR service.
– Actually, NAPTR RR is defined in RFC2915.

• Format of ENUM NAPTR RR
label IN NAPTR order pref “u” “E2U+enumservice” regexp .
– label: domain name format of E.164 number– order: 16bit unsigned integer– pref: 16bit unsigned integer (order is priority)– enumservice: specifies what type of URI can be used for– regexp: specifies how AUS be replaced

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Examples of ENUM NAPTR
In case of telephone number +81352972571$ORIGIN 1.7.5.2.7.9.2.5.3.1.8.e164.arpa.
IN NAPTR 100 10 “u” “E2U+sip” “!^+813(.*)$!sip:¥1@sipisp.jp!” .
Results in ‘sip:52972571@sipisp.jp’$ORIGIN 1.7.5.2.7.9.2.5.3.1.8.e164.arpa.
IN NAPTR 100 10 “u” “E2U+sip” “!^.*$!sip:info@sip.jprs.jp!” .
Results in ‘sip:info@sip.jprs.jp’$ORIGIN 1.7.5.2.7.9.2.5.3.1.8.e164.arpa.
IN NAPTR 100 10 “u” “E2U+mailto” “!^.*$!mailto:info@jprs.jp!” .
Results in ‘mailto:info@jprs.jp’

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ENUM Services••Must be published as RFC and registered to IANA.
Expected ENUM services, protocols.
Service/Protocl

service field

URI Scheme (EX)

SIP
H.323
InternetFAX
Telephone
FAX
EmailWEB

E2U+sip
E2U+h323
E2U+ifax
E2U+telE2U+fax:tel
E2U+email:mailto
E2U+web:httpsip:info@sip.jprs.co.jp
h323:info@h323.jprs.co.jp
mailto:fax@fax.jprs.co.jp
tel:+81352972571;svc=voice
tel:+81352972571;svc=fax
mailto:info@jprs.co.jp
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Japan Registry ServiceRelated Standards• EPP – Extensible Provisioning Protocol– For provisioning ENUM NS / NAPTR data between
ENUM registries and registrars.
– Standardization is work in progress at IETF.

• CRISP – Cross Registry Information Sharing
Protocol– For referring ENUM NS registrant data.
– Standardization is work in progress at IETF.

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Japan Registry ServiceLayer of ENUM services and standards

Communication service (multiple carriers)
Authentication, Social Security
Communication service (single carrier)
Provisioning, Communication Security
Applications/Terminals
SIP, Mail, Web, etc.
Infrastructure
ENUM DNS
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ENUM Structure

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Tiered Architecture• Model of ENUM DNS layer considered at ITU-T.
• Tier0: Top of the ENUM DNS layer.
– e164.arpa.
– Managed by ITU-T, Operated by RIPE/NCC.

• Tier1: E.164 country code ENUM DNS layer.
– 1.8.e164.arpa. (Japan)– Management and operation are domestic matter.

• Tier2: Terminal (NAPTR RRs) ENUM DNS layer.
– 1.7.5.2.7.9.2.5.3.1.8.e164.arpa.
– Management and operation are domestic matter.
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Tier structure: example 1• Tier1 delegates numberblock(s) to Tier2.

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Tier structure: example 2• Tier1 is layered
according to number plan.
• Tier1 delegates numberblock(s) to Tier2.

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Tier structure: example 3• Tier1 delegates eachnumber to Tier2.
• Easy to provide number
portability.
• Suitable for user ENUM.

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Operator ENUM / User ENUM
• Operator ENUM
– Operators (Carriers, ISPs, etc.) set NAPTR to each number they
assigned.
• ENUM services may be limited.

– Used for inter-routing within operators.
– ENUM DNS can be internal to the operators.
• NAPTR RRs can be hidden from users.

• User ENUM
– Users (E.164 number holders) set NAPTRs according to theirdemands.
• Variety of ENUM services can be chosen.

– User must be verified whether appropriate number holder.
• Independent number verification authority is required.

• Operation styles are completely different.
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ENUM TrialRIPE NCC
Tier0

ITU-T TSBCountryCountryCountry
Tier1
DNS Operator

Tier2
DNS Operator

Registry /Registrar

Registry /Registrar

User

User

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ENUM trial situation in the World• Promoted by an organization for the ENUM trial.
– Members are consist from registry, government, telecom carriers,ISPs, vendors, etc.
– AT, UK, SE, etc.
– Most of ENUM trials are this style.

• Promoted by mainly ccTLD registry.
– Member structure is almost the same as above.
– DE, KR, etc.

• Promoted by government.
– ccTLD is a member of the trial.
– CN, SG, etc.

• Promoted by company authorized by government.
– AM, Islands.

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Why ccTLD?
• ENUM may become critical infrastructure.
• Relationship between government.
• Relationship between carriers/ISPs.
• Stable DNS and Registry/Registrar operation isimportant.

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Delegation status

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ENUM Operation

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Typical ENUM world
SIP ServerIP NetworkMGWInternetPSTN

Location Servre Mail, iFax,SMS, etc.

PSTN

IP Network
ENUM Service
For Telecom carriers

ENUM ServiceFor Enterprises

ENUM Infrastructure

ENUM Service
For End Users
PBX

Tier1
Registry/Registrar

ENUM
DNS

Tier2
Registry/Registrar
APIENUM
Application

ENUM Application
ENUM Terminal, etc.

Copyright © 2003 JPRSENUM Application
ENUM Terminal, etc.

ENUM Application
ENUM Terminal, etc.

ENUM Registrant
/ ASP

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TelecomCarriersJapan Registry Service

DNS structure design• Depends on which model to select.
• Typical requirements for Tier1 DNS:
– Handling of large zone (up to 100M entry).
– Scalability and stability.
– Performance.

• Typical requirements for Tier2 DNS:
– Capability for frequent update.
– Relationship with registry database.
– EDNS0 support.
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Japan Registry ServiceRegistry DB• Tier1:– Frequency of zone generation.
– Zone transfer method to primary DNS.
• Authentication and consistency.

– Interface for Tier2 Registry (or Tier1 Registrar).
• EPP?

• Tier2:– Partial (dynamic) update.
– Interface for User (or Tier2 Registrar).
• Validation of number holder.

– Interface for Tier1 Registry (or Registrar).
• EPP?

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Japan Registry ServiceConsideration for DNS• Typical ENUM services like Web, Mail, SIP are
also lookups DNS.
– Web: Hyper-links(A).
– Mail: sending (MX, A), receiving (PTR).
– SIP: sip domain(A), service protocol (D2U/D2T
NAPTR), service location(SRV)• DNS queries will increase when ENUM deployed.
• Users are nervous to service quality.
– Users don’t care where is the bottle neck.

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Japan Registry ServiceIssues• Future vision, business model.
– Operator ENUM / User ENUM.
– Management Entity, responsibility.
– Charge.

• DNS operation.
– Tier structure.
– DNS server distribution.
– Provisioning of NAPTR data.

• Application software development.
– ENUM client.
• Relation with other applications, such as Mailer, SIP phone, etc.

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Issues (cont.)• Security.
– DNS data.
– ENUM provisioning.
– User communication (application level).

• Privacy.
– End user data (whois).
– Trace of the user behaviour.

• Regulation.
– ENUM numbering plan.
– Guarantee of quality of service.
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ENUM activities in JapanCopyright © 2003 JPRSJapan Registry ServiceENUM Study Group•

Established– September 2002.

•Objectives– Understanding the ENUM technology : desk work.
– Finding political/regulatory issues related to ENUM-basedimplementation and operation.
– Studying the implementation and operation of the ENUM–based system,and related matters.
– Finding technological issues related to ENUM.
– Clarifying pros and cons in ENUM usage.

•Target of the study– ENUM technology.
– Related technology such as DNS，URI，DDDS.

•Final report– Published on May 2003 (English translation coming soon).

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Japan Registry ServiceENUM Trial Japan (ETJP)•

Established– on 17 September 2003 (1 year activity).

•Purpose– Perform ENUM trials to ensure functioning and feasibility of basic technicalfacility.
– Demonstration of technology for international use.
– Accumulation of know-how on ENUM and sharing of it among participants.

•Activities– DNS operation for ENUM Trial.
– Feasibility test of communication applications (device, software) using ENUM.
– Feasibility test of communication services.

•Results– Results of technical verification.
• Communication devices and software provided by participants.
• Communication services.

– Clarification and consideration of relevant issues.

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ETJP organization• Participants– Companies, organizations, and individuals who hope to contributeto ETJP activities.
– Number of members: 42 (as of 21 Nov 2003).

• Officers– Chairman• Shigeki Goto
Japan Network Information Center (JPNIC)/Waseda University– Vice chairman• Hirofumi Hotta
Japan Registry Service Co., Ltd.(JPRS)• Yoshiki Ishida
WIDE Project

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Japan Registry ServiceENUM trial (phase1)
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Japan Registry ServiceENUM
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Japan Registry ServiceENUM trial (phase3)
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End userNPSTS IPile-ma ・・・39Japan Registry ServiceReferences• IETF ENUM WG– http://www.ietf.org/html.charters/enum-charter.html• ITU-T– http://www.itu.int/osg/spu/enum/• RIPE NCC– http://www.ripe.net/enum/• ETJP / ENUM Study Group– http://etjp.jp/– http://www.nic.ad.jp/en/
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Japan Registry ServiceQ&A

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