Patent ID: 8554925

Claim:
A method of bidirectional address conversion in Session-Initiated-Protocol (“SIP”)-controlled data streams between IPv4-enabled data terminals and IPv6-enabled data terminals, using an address converter and an SIP server, comprising: an IPv6-enabled data terminal transmitting a first invite message to an IPv4-enabled data terminal to initiate a connection, the IPv6-enabled data terminal being a calling party for the connection being initiated via the first invite message and the IPv4-enabled data terminal being a called party for the connection being initiated via the first invite message; the IPv4-enabled data terminal transmitting a response message to the IPv6-enabled data terminal in response to receiving the first invite message from the IPv6-enabled data terminal, the response message indicating the first invite message is not acceptable at the Ipv4-enabled data terminal; the SIP server intercepting the response message, the SIP server foregoing forwarding of the response message to the IPv6-enabled data terminal; the address converter generating an IPv4 address for the IPv6-enabled data terminal in response to the SIP server intercepting the response message; the SIP server sending a second invite message to the IPv4-enabled data terminal, the second invite message comprising the generated IPv4 address; the IPv4-enabled data terminal sending a ringing message to the SIP server, the ringing message confirming receipt and validity of the second invite message by the IPv4-enabled data terminal; the address converter receiving an IPv4 address of the IPv4-enabled data terminal; the address converter generating an IPv6 address for the IPv4-enabled data terminal in response to receiving the IPv4 address of the IPv4-enabled data terminal; the SIP server modifying the ringing message, wherein modifying the ringing message comprises replacing a target address of the IPv4-enabled data terminal in the ringing message with the generated IPv6 address; the SIP server transmitting the modified ringing message to the IPv6-enabled data terminal; the IPv4-enabled data terminal sending a confirmation message to the SIP server, the confirmation message confirming successful establishment of the connection; the SIP server receiving the confirmation message and modifying the confirmation message, wherein modifying the confirmation message comprises replacing a target address of the IPv4-enabled data terminal in the confirmation message with the generated IPv6 address; and the SIP server transmitting the modified confirmation message to the IPv6-enabled data terminal.