Patent ID: 8627445

Claim:
A proxy connection method of operating an adapter for connecting an IPv4-compliant client having a SIP (Session Initiation Protocol) function, to a SIP server which is connected with a first IPv6 network, via a second IPv4 network and an access gateway, the IPv4-compliant client being connected with the second IPv4 network, wherein the adapter is connected with the second IPv4 network, the method comprising: receiving a first REGISTER message from the client via the second IPv4 network, the first REGISTER message being for requesting the SIP server to register position information of the client, and the first REGISTER message having an IPv4 address of the client; upon reception of the first REGISTER message, establishing a tunnel connection between the adapter and the access gateway on the second IPv4 network, to thereby allow use of an IPv6 address for communication between the adapter and the access gateway, via the second IPv4 network; upon establishment of the tunnel connection, retrieving an IPv6 address of the access gateway via the established tunnel connection, and generating a second REGISTER message from the first REGISTER message, the second REGISTER message having the retrieved IPv6 address of the access gateway; sending the second REGISTER message to the SIP server through the tunnel connection, the access gateway and the first IPv6 network sequentially, to thereby allow the SIP server to register the position information of the client as the same address as the IPv6 address of the access gateway; and disconnecting the tunnel connection upon completion of the registration of the position information of the client at the SIP server, wherein use of the tunnel connection allows address translation for the client between the first IPv6 network and the second IPv4 network, to thereby allow the IPv4-compliant client to be connected to an IPv6-compliant client which is connected with the first IPv6 network.