1. Numbering and Interconnection Options
John Horrocks

2. Identification (seen by user)
“Private identity” used for registration
“Public identity” used for user-user communications
E.164 (normally has to be portable)
SIP addresses
operator> (not portable, changeable - LIMITED VALUE)
domain> (portable, users will want to use current addresses)

3. Main SIP address options for use in Protocols
E.164 only
E.164 plus serving operator
operator>”
Name plus serving operator
operator>”
User domain address
(can add
routing number)
Which?
Which operator serves?

4. Routing options - 1 Step-by-Step (used for E.164) B  m B  n B  o
B  p
B  q A B m n o p q 1 2 3 4 5
Needs knowledge of B
Step-by-Step with portability (used for E.164)
B  5 5  p
B m
B  n
B  o
B  q A B m n o p q 1 2 3 4 5
Edge of portability domain

5. Routing options - 2 Open backbone B  5 5  p B  m B  q A B m p q 1
Needs knowledge of B
Common “ENUM” for E DNS
B  5
5  p
B  m
B  q A B m p q 1
Common backbone 5
Whose?
Internet
Needs knowledge of B
Common “ENUM” for E DNS
B  5
B  q A B q 5 1
Internet
Which?

6. Numbering + Routing options
User ID
Routing
Finding i/c point
Networks need
Comment
E.164
Step/Step
All #s in local NP
All initial digits cc+
Routing table
Internal ENUM+DNS
Available
Emulation
Backbone
All #s, or
Same as Step/Step
Global ENUM+DNS
Or same as Step/Step
Global ENUM+DNS preferable
<srvg op>
All <srvg op>s
Global DNS
Global DNS essential
<user dom>
All user domains

7. Possible Conclusions
PSTN Emulation services using E.164 are possible now
Each operator needs internal ENUM/DNS for E.164
If E.164 is supported and a common backbone is used, then need global ENUM or published routings to national server
Identification using domain” is not possible without additional shared infrastructure, ie global DNS

8. Questions
Can users use existing <user domains> eg addresses?
Will Global DNS for NGN be part of Internet DNS? If not, who will provide it?
Will a shared ENUM for NGN be public carrier ENUM? If not, who will provide it?
If the public Internet ENUM/DNS is used what connectivity will there be with the Internet?
Are telcos starting down the slippery slope of migrating onto the Internet?

9. Isolated networks - E.164 DNS (ENUM) Public (User ENUM)
Public Internet
NAT
LAN
Call Server
Call Server
Call Server
Call Server
Private IP
NGN-1
NGN-2
NGN-3
NGN-4
Private IP
Private IP
Private IP
Private IP
DNS
(ENUM)
DNS
(ENUM)
DNS
(ENUM)
DNS
(ENUM)
For own numbers
Network
termination point
(Gateway)
Session Border Controllers
Number  SIP of I/c point
SIP  private IP

10. Isolated networks, public ENUM - E.164
Cannot do IP address as serving net server only
has private address
DNS
(ENUM)
Public (Carrier ENUM)
Number  SIP of serving network server
Public Internet
NAT
Call Server
(with barrier)
Call Server
(with barrier)
Call Server
(with barrier)
Call Server
(with barrier)
LAN
Private IP
NGN-1
NGN-2
NGN-3
NGN-4
Private IP
Private IP
Private IP
Private IP
DNS
DNS
DNS
DNS
network server>
Network
termination point
(Gateway)
Session Border Controllers
SIP of serving network server  SIP of I/c point
SIP  private IP

11. Common backbone - E.164 (GSMA)
DNS
(ENUM)
Public (User ENUM)
Public Internet
NAT
LAN
Call Server
Call Server
Backbone
Private IP
NGN-1
NGN-4
Public IP
Private IP
Private IP
DNS
(ENUM)
network server>
NGN (Carrier ENUM)
Network
termination point
(Gateway)
Number  SIP of serving network server
SIP  public IP

12. Common backbone, public DNS/ENUM - E.164
Public (Carrier ENUM)
Number  SIP of serving network server
SIP  public IP
Public Internet
NAT
Call Server
(with barrier)
Call Server
(with barrier)
LAN
Backbone
Private IP
NGN-1
NGN-4
Private IP
Public IP
Private IP
network server>
Network
termination point
(Gateway)

13. Common backbone - user@user domain
DNS
Public
Public Internet
NAT
LAN
Call Server
Call Server
Backbone
Private IP
NGN-1
NGN-4
Public IP
Private IP
Private IP
DNS
domain>
NGN
New process needed
Network
termination point
(Gateway)
domain  SIP of serving network server
SIP  public IP

14. Public DNS - user@user domain
New process needed
domain  SIP of serving network server
SIP  public IP
Public Internet
NAT
Call Server
(with barrier)
Call Server
(with barrier)
LAN
Backbone
Private IP
NGN-1
NGN-4
Private IP
Public IP
Private IP
Session Border Controller
Network
termination point
(Gateway)