THIS IS THE WAY

ENUM Variants

Jim McEachern

Carrier VoIP Standards Strategy

THIS IS

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ENUM Variants

• User ENUM

• Infrastructure ENUM

• Private ENUM

• Enterprise ENUM

• ENUM to enable new business models

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Important Aspects of ENUM

• Access• Public DNS (e164.arpa) or Private?

• Content• User URI (AoR) or Interconnection URI?

• Control of content • End user opt-in & control, or carrier control?

• Routing decision• originating end user, terminating end user, or carrier?

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ENUM for Dummies

Public(e164.arpa)

Private

User URI Interconnect URI

UserENUM

InfrastructureENUM

PrivateENUM

InfrastructureENUM?

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Who is in Control?

Public(e164.arpa)

Private

User URI Interconnect URI

UserENUM

InfrastructureENUM

PrivateENUM

InfrastructureENUM?Carri

er Contro

l

Carrier C

ontrol

End Useropt-in

End Useropt-in

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ENUM Variants

• User ENUM

• Infrastructure ENUM

• Private ENUM

• Enterprise ENUM

• ENUM for new business model

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User ENUM (SIP) Call Flow

1. The caller simply dials the person’s normal telephone number

2. Calling party proxy UAC queries DNS for location of end point

3. DNS returns NAPTR record containing SIP URL

4. Calling party UA connects the call

ENUM Global Directory (DNS) Equates +1-202-555-1234 to sip:name@domain.com to enable Voice over IP using SIP

ENUM Global Directory (DNS) Equates +1-202-555-1234 to sip:name@domain.com to enable Voice over IP using SIP

ENUM typically illustrated like this, but…ENUM typically illustrated like this, but…

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User ENUM vs. SIP

User ENUM query can return a single response, or multiple responses, with priority indicated.

sipping WG (RFC 3824) recommends returning a single SIP address-of-record, and letting SIP mechanisms deal with priorities, capabilities, preference, presence & redirection.

User ENUM allows multiple entries, including priorities and capabilities. SIP, H.323, mobile, messages, email, etc. can even return another E.164 number duplicates functionality in SIP no consensus on which should be used

User ENUM provides user preferences for being reached hints to help the caller decide where to direct the call nothing requires the caller to follow those preferences

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Alternative User ENUM/SIP Call Flow

1. Caller dials normal phone number

2. SIP UAC queries DNS for location of end point

3. DNS returns NAPTR record containing SIP URL to Calling Party UA

4. Caller’s UA initiates call with SIP URL

ENUM Global Directory (DNS) Equates +1-613-555-1234 to sip:jmce@domain.com to enable Voice over IP using SIP

ENUM Global Directory (DNS) Equates +1-613-555-1234 to sip:jmce@domain.com to enable Voice over IP using SIP

ENUM query can be done by VoIP clientENUM query can be done by VoIP client

ENUM

SIPProxy

SIPProxyDial

+1-613-555-1234

Query4.3.2.1.5.5.5.3.1.6.1.e164.arpa?

Responsesip:jmce@domain.com

SipSip:jmce@domain.com

Call Setup

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User ENUM for Routing?

ENUM

Carrier A Carrier B

SIPProxy

SIPClient

B

SIPProxy

SIPClient

A

Internet

??

??

??

User ENUM cannot provide routingUser ENUM cannot provide routing

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ENUM Variants

• User ENUM

• Infrastructure ENUM

• Private ENUM

• Enterprise ENUM

• ENUM for new business model

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Infrastructure ENUM

I-ENUM

Carrier A Carrier B

SIPProxy

SIPClient

B

SIPProxy

SIPClient

A

Internet

Infrastructure ENUM identifies interconnect pointInfrastructure ENUM identifies interconnect point

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VoIP Peering

• IETF SPEERMINT WG is addressing VoIP peering problem in cooperation with Infrastructure ENUM

• Infrastructure ENUM identifies the carrier of record, but…• if you have a business relationship, you already know the

interconnection point for that carrier.• if you don’t have a business relationship, you probably won’t be

allowed to directly interconnect anyway.

What problem is SPEERMINT solving?What problem is SPEERMINT solving?

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ENUM Variants

• User ENUM

• Infrastructure ENUM

• Private ENUM

• Enterprise ENUM

• ENUM for new business model

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ENUM for 3GPP IMS

• IMS specifies that all routing shall be based on SIP URI• E.164 numbers shall be translated to SIP URI using ENUM, “or any

other suitable translation database”

• ENUM in IMS must be Private ENUM • full SIP URI required for routing• data privacy laws • competitive information

• Infrastructure ENUM can be used to interconnect between IMS networks

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IMS - Private ENUM

I-ENUM

Carrier A Carrier B

SIPProxy

SIPClient

B

SIPProxy

SIPClient

A

Internet

Private ENUM Translates E.164 - to - URIPrivate ENUM Translates E.164 - to - URI

P-ENUM

P-ENUM

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ENUM Variants

• User ENUM

• Infrastructure ENUM

• Private ENUM

• Enterprise ENUM

• ENUM for new business model

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Enterprise ENUM

ENUM

Carrier A Carrier B

SIPProxy

SIPClient

C

SIPPBX

SIPClient

A

Internet

Enterprise ENUM can take many forms Enterprise ENUM can take many forms

SIPClient

B

Internal translationfrom E.164 to SIP URI

Internal translationfrom E.164 to SIP URI

1 2 3

ENUM

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Enterprise ENUM

Public(e164.arpa)

Private

User URI Interconnect URI

UserENUM

InfrastructureENUM

PrivateENUM

InfrastructureENUM?

32

1

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ENUM Variants

• User ENUM

• Infrastructure ENUM

• Private ENUM

• Enterprise ENUM

• ENUM for new business model

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New ENUM Applications - vCard

ENUM

Carrier A Carrier B

SIPProxy

SIPClient

B

SIPPBX

SIPClient

A

Query based on originating E.164 number Query based on originating E.164 number

vCard

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New ENUM Applications - CNAM

Carrier A Carrier B

SIPProxy

SIPClient

B

SIPPBX

SIPClient

A

Query based on originating E.164 number Query based on originating E.164 number

P-ENUM

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Summary

•When ENUM is specified, which variant is intended?

•ENUM flavors are reasonably orthogonal • With clear rules they could be completely orthogonal

•Many interesting applications for ENUM will use Private ENUM

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Thank you