Numbering and Interconnection Options John Horrocks +44 1483 797807 john@horrocks.co.uk

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 User@<serving operator> (not portable, changeable - LIMITED VALUE) User@<user domain> (portable, users will want to use current email addresses)

Main SIP address options for use in Protocols E.164 only “+441483797000@dummy” E.164 plus serving operator “+441483797000@<serving operator>” Name plus serving operator “JohnSmith@<serving operator>” User domain address “John@smith.co.uk” (can add routing number) Which? Which operator serves?

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

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.164 + 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.164 + DNS B  5 B  q A B q 5 1 Internet Which?

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 User@ <srvg op> All <srvg op>s Global DNS Global DNS essential User@ <user dom> All user domains

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 “user@user domain” is not possible without additional shared infrastructure, ie global DNS

Questions Can users use existing <user domains> eg email 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?

Isolated networks - E.164 DNS (ENUM) Public (User ENUM) Public Internet NAT SIP:<E164>@<dummy> 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

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 SIP:<E164>@<serving network server> Network termination point (Gateway) Session Border Controllers SIP of serving network server  SIP of I/c point SIP  private IP

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) SIP:<E164>@<serving network server> NGN (Carrier ENUM) Network termination point (Gateway) Number  SIP of serving network server SIP  public IP

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 SIP:<E164>@<serving network server> Network termination point (Gateway)

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 SIP:<user>@<user domain> NGN New process needed Network termination point (Gateway) User@user domain  SIP of serving network server SIP  public IP

Public DNS - user@user domain New process needed User@user 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)