ENUM Overview

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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


User ENUM
Infrastructure ENUM
Public (e164.arpa)
Private ENUM
Infrastructure ENUM?
Private
User URI
Interconnect URI
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Who is in Control?


User ENUM
Infrastructure ENUM
End User opt-in
Public (e164.arpa)
Private ENUM
Infrastructure ENUM?
Carrier Control
Private
User URI
Interconnect URI
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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
ENUM Global Directory (DNS) Equates
1-202-555-1234 to sipname_at_domain.com to enable
Voice over IP using SIP
3. DNS returns NAPTR record containing SIP URL
2. Calling party proxy UAC queries DNS for
location of end point
1. The caller simply dials the persons normal
telephone number
4. Calling party UA connects the call
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
ENUM Global Directory (DNS) Equates
1-613-555-1234 to sipjmce_at_domain.com to enable
Voice over IP using SIP
ENUM
3. DNS returns NAPTR record containing SIP URL to
Calling Party UA
2. SIP UAC queries DNS for location of end point
Response sipjmce_at_domain.com
Query 4.3.2.1.5.5.5.3.1.6.1.e164.arpa?
Call Setup
1. Caller dials normal phone number
Sip Sipjmce_at_domain.com
SIP Proxy
SIP Proxy
Dial 1-613-555-1234
4. Callers UA initiates call with SIP URL
ENUM query can be done by VoIP client
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User ENUM for Routing?
ENUM
?
SIP Client B
?
SIP Client A
Carrier B
Carrier A
?
User 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
SIP Client B
SIP Client A
Carrier B
Carrier A
Infrastructure 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 dont have a business relationship, you
  probably wont be allowed to directly
  interconnect anyway.

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
P-ENUM
SIP Client B
SIP Client A
Carrier B
Carrier A
Private ENUM Translates E.164 - to - URI
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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
Internal translation from E.164 to SIP URI
SIP Client B
ENUM
ENUM
1
2
3
SIP Client C
SIP Client A
Carrier B
Carrier A
Enterprise ENUM can take many forms
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Enterprise ENUM


User ENUM
Infrastructure ENUM
3
Public (e164.arpa)
2
Private ENUM
Infrastructure ENUM?
1
Private
User URI
Interconnect URI
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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
vCard
ENUM
SIP Client B
SIP Client A
Carrier B
Carrier A
Query based on originating E.164 number
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New ENUM Applications - CNAM
P-ENUM
SIP Client B
SIP Client A
Carrier B
Carrier A
Query based on originating E.164 number
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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