Inter-connection among VOIP domains based on ENUM

Today, domestic or international Carriers have to make indirect IP->PSTN->IP communication recuring to PSTN, because the lack of uniform sharing address resources. This situation greatly affects communication efficiency and running cost.

Carrier ENUM can help us set up the sharing address resources library between the domestic carriers and the international carriers and realize inter-connection of IP->IP.

One-number business

Enum resource record can store various of information such as telphone-number, mobile-number, IP-terminal's address, email-address. It provides a effective solution of all-business-one-number for carriers.

Carrier ENUM for multi-media message service

MMSC of mobile core network is a kind of internet device. If mobile phone A sends a multimedia message to mobilephone B, the message will first reach A'attributive MMSC A,then MMSC A will send a query to the ENUM dns. After getting a response from the ENUM dns which contains the address of mobile phone B's attributive MMSC B, MMSC A will send the message to MMSC B, then MMSC B will transfer the message to mobile phone B. Carrier ENUM can store the location information of MMSC. It can provide addressing for services and allow adding more network devices without changing present network architecture.

ENUM application in 3G

3G core-networek IMS is based on pure IP. Carrier ENUM provides a global and inter-carrier addressing framework for IMS. For example, a mobile user UE#1 of carrier A calls another mobile user UE#2 of carrier B. Call control server S-CSCF A locates the callee's network I-CSCF with the help of ENUM resolution server, the I-CSCF transfers the call to the UE#2's attributive S-CSCF B, then the S-CSCF B gets the address of UE#2, and finally sets up the call link from UE#1 to UE#2.