1. THIS IS THE WAY
ENUM Variants
Jim McEachern
Carrier VoIP Standards Strategy
THIS IS

2. ENUM Variants
User ENUM
Infrastructure ENUM
Private ENUM
Enterprise ENUM
ENUM to enable new business models

3. 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?

4. User ENUM Infrastructure ENUM Private ENUM Infrastructure ENUM?
ENUM for Dummies
User
ENUM
Infrastructure
ENUM
Public
(e164.arpa)
Private
ENUM
Infrastructure
ENUM?
Private
User URI
Interconnect URI

5. Carrier Control 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

6. ENUM Variants
User ENUM
Infrastructure ENUM
Private ENUM
Enterprise ENUM
ENUM for new business model

7. User ENUM (SIP) Call Flow
ENUM Global Directory (DNS) Equates to 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 person’s normal telephone number
4. Calling party UA connects the call
ENUM typically illustrated like this, but…

8. 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, , 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

9. Alternative User ENUM/SIP Call Flow
ENUM Global Directory (DNS) Equates to 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
Query
e164.arpa?
Call Setup
1. Caller dials normal phone number
Sip
SIP
Proxy
SIP
Proxy
Dial
4. Caller’s UA initiates call with SIP URL
ENUM query can be done by VoIP client

10. User ENUM cannot provide routing
User ENUM for Routing?
ENUM
SIP
Proxy
SIP
Proxy ? ?
SIP
Client B
SIP
Client A
Carrier B
Carrier A
Internet ?
User ENUM cannot provide routing

11. ENUM Variants
User ENUM
Infrastructure ENUM
Private ENUM
Enterprise ENUM
ENUM for new business model

12. Infrastructure ENUM identifies interconnect point
I-ENUM
SIP
Proxy
SIP
Proxy
SIP
Client B
SIP
Client A
Carrier B
Carrier A
Internet
Infrastructure ENUM identifies interconnect point

13. What problem is SPEERMINT solving?
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?

14. ENUM Variants
User ENUM
Infrastructure ENUM
Private ENUM
Enterprise ENUM
ENUM for new business model

15. IMS specifies that all routing shall be based on SIP URI
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

16. Private ENUM Translates E.164 - to - URI
IMS - Private ENUM
I-ENUM
P-ENUM
P-ENUM
SIP
Proxy
SIP
Proxy
SIP
Client B
SIP
Client A
Carrier B
Carrier A
Internet
Private ENUM Translates E to - URI

17. ENUM Variants
User ENUM
Infrastructure ENUM
Private ENUM
Enterprise ENUM
ENUM for new business model

18. Enterprise ENUM can take many forms
Internal translation
from E.164 to SIP URI
SIP
Client B
ENUM
ENUM 1 2 3
SIP
Proxy
SIP
PBX
SIP
Client C
SIP
Client A
Carrier B
Carrier A
Internet
Enterprise ENUM can take many forms

19. 3 2 1 Enterprise ENUM User ENUM Infrastructure ENUM Private ENUM
Public
(e164.arpa) 2
Private
ENUM
Infrastructure
ENUM? 1
Private
User URI
Interconnect URI

20. ENUM Variants
User ENUM
Infrastructure ENUM
Private ENUM
Enterprise ENUM
ENUM for new business model

21. New ENUM Applications - vCard
SIP
Proxy
SIP
PBX
SIP
Client B
SIP
Client A
Carrier B
Carrier A
Query based on originating E.164 number

22. New ENUM Applications - CNAM
P-ENUM
SIP
Proxy
SIP
PBX
SIP
Client B
SIP
Client A
Carrier B
Carrier A
Query based on originating E.164 number

23. When ENUM is specified, which variant is intended?
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

24. Thank you