12 January 2006 CDG Conference Call Integrating Existing Number Portability Solutions in Carrier-ENUM Douglas Ranalli, NetNumber, Inc.

2 About NetNumber Provider of next generation addressing solutions to carriers and operators based on the NetNumber TITAN platform. –Transactional IP-Telephony Addressing & Numbering (TITAN) Common transaction platform in operator’s network for both SS7/C7 and IP Addressing: –Number-Portability, Flexible-Numbering (GTT), etc: Multiple protocols: –AIN 0.2, PCS-1900, GSM/MAP, IS-41, INAP, DNS, SIP and ENUM. Multiple interfaces: –T1/E1 low-speed link, SIGTRAN and IP. –Carrier-ENUM: Flexible implementation options for the discovery of carrier-controlled IP-services. ENUM query: –Different address resolution models can be configured on a country-by-country basis. –Up to 43,000 transactions/second on a single TITAN Edge server. SIP Invite with 302 redirect: –SIP Invite to a TEL URI results in a SIP 302 “temporarily moved” response with one or more SIP URIs as contact addresses. –Up to 15,000 transactions/second on a single TITAN Edge server.

3 Customer/Partner Examples

4 Carrier-ENUM Background Private service discovery infrastructure. Accessed by all types of carriers. Common domain name: “e164enum.net” Standard query/response protocol as defined by RFC Supports number-portability. Focus of this presentation : –Carrier-ENUM implementation models that leverage existing number-portability solutions.

5 IMS ENUM Call-Flow Example 1.End-user dials E.164 to initiate service. 2.S-CSCF issues ENUM service discovery query to on-site or hosted ENUM server for a SIP-URI. 3.S-CSCF resolves host name within SIP URI using on-site or hosted private DNS infrastructure. 4.S-CSCF sends SIP Invite to destination I-CSCF. 5.I-CSCF queries HSS to get address of S-CSCF. 6.I-CSCF proxies Invite to destination S-CSCF. 7.Standard SIP/SDP session negotiation follows.

6 ENUM Implementation Options DNS Delegation –ENUM service discovery via DNS delegation through Tier-0, Tier-1, Tier-2 infrastructure. Central Portability Database –Central portability database fulfills role of Tier-0 and Tier-1 for a given country. Solution utilized by GSM, CDMA and GRX/CRX interconnect providers in North America today. Number-Block Assignment –Existing number-block assignment data fulfills the role of Tier-0 and Tier-1 for any non-ported network. Simple extension of model being used in North America today. IMSI Query –MAP query for IMSI address fulfills the role of Tier-0 and Tier-1 for any carrier/operator that supports IMSI addressing. Solution being used by GSM operators in Europe today to interconnect MMS.

7 DNS Delegation 2.S-CSCF issues ENUM service discovery query to on-site or hosted ENUM server for a SIP-URI. a.ENUM Server queries Tier-0 to identify a country-specific Tier-1 then queries the Tier-1 to identify the destination operator (NS record of operator’s Tier-2 name server). b.ENUM server queries the destination Tier-2 nameserver to get a NAPTR record identifying an appropriate network entry-point (I-CSCF address) in the form of a SIP URI.

8 Central Portability Database 2.S-CSCF issues ENUM service discovery query to on-site or hosted ENUM server for a SIP-URI. ENUM Server checks for locally provisioned portability data to identify the destination operator then checks for locally provisioned interconnect data to discover an appropriate I- CSCF address (or NS record) for the destination operator. Key Benefits: Resolution is extremely fast. No Tier-1 or Tier-2 wide area network queries required. Originating operator can locally provision an appropriate interconnect address for a destination partner.

9 Number-Block Assignment 2.S-CSCF issues ENUM service discovery query to on-site or hosted ENUM server for a SIP-URI. ENUM Server checks for locally provisioned number-block assignment data to identify the destination operator then checks for locally provisioned interconnect data to discover an appropriate I-CSCF address (or NS record) for the destination operator. Key Benefits: Resolution is extremely fast. No Tier-1 or Tier-2 wide area network queries required. Originating operator can locally provision an appropriate interconnect address for a destination partner.

10 IMSI Query 2.S-CSCF issues ENUM service discovery query to on-site or hosted ENUM server for a SIP-URI. ENUM server issues MAP query for an IMSI address to identify the destination operator then checks for a locally provisioned I-CSCF address (or NS record) for the destination operator. Key Benefits: Leverages existing operator investment in IMSI addressing to fulfill Tier-0 and Tier-1 function. Originating operator can locally provision an appropriate interconnect address for a destination partner. Solution already being used to interconnect MMS services today.

11 Recommendation Document multiple options for integrating existing number-portability solutions in Carrier-ENUM. –Operators and GRX/CRX/IPX providers will benefit from flexibility. Various Carrier-ENUM implementations work equally well in on- site or hosted ENUM server deployments. Different solutions can be applied to different country-codes. –Solutions can be enhanced by use of third-party interconnect registries. Multiple interconnect registries available today or under development. Interconnect registries facilitate the exchange of appropriate interconnect data (points of interconnect) between carriers/operators. –Eliminate requirement for manual entry of interconnect data. –More sophisticated than wide-area-network query to a Tier-2 nameserver. »Different interconnect addresses for different partners.