Patent ID: 7403522

Claim:
A method of relaying at least one IPv6 multicast packet to be transmitted via an IPv6 network to at least one IPv4 network, comprising the steps of: receiving a message requesting reception of an IPv4 multicast packet including an IPv4 multicast address as a destination address, from the at least one IPv4 network; storing the IPv4 network which transmits the message as a network requesting reception of the IPv4 multicast packet in correspondence with an IPv6 multicast address corresponding to the IPv4 multicast address; receiving an IPv6 multicast packet including an IPv6 multicast address as a destination address, from the at least one IPv6 network; generating, from the IPv6 multicast packet, an IPv4 multicast packet which includes, as a destination address, the IPv4 multicast address corresponding to the IPv6 multicast address contained as a destination address in the IPv6 multicast packet; and transmitting the IPv4 multicast packet thus generated to the IPv4 network stored in correspondence with the IPv6 multicast address.