Patent ID: 8902880

Claim:
A local terminal device in electronic communication with a dynamic domain name service (DDNS) server and a remote terminal device via a voice over Internet protocol (VoIP) network, the local terminal device having a local Internet protocol (IP) address, the remote terminal device having a remote IP address, the local terminal device comprising: a user interface operable to receive a local mail address of a local user and a remote mail address of a remote user; at least one processor; a storage system to store one or more programs executable by the at least one processor, the one or more programs comprising instructions for: converting the local mail address into a local domain name according to a first hash function and transmitting the local domain name and the local IP address to the DDNS server to register with the DDNS server, wherein the first hash function comprises combining characters of the local mail address and a predefined string to form the local domain name; converting the remote mail address into a remote domain name according to a second hash function and querying the DDNS server for the remote IP address corresponding to the remote domain name, wherein the second hash function comprises combining characters of the remote mail address and a predefined string to form the remote domain name; and exchanging VoIP signaling with the remote terminal device according to the remote IP address.