Tunneling method and apparatus for multicasting between IPv4 network and IPv6 network

A tunneling method for multicasting between an IPv4 network and an IPv6 network, said method comprising the steps of:

• setting a multicast table containing information about receive and transmit interfaces in a multicast delivery tree structure for each of the IPv4 network and the IPv6 network;
• assigning a multicast address area to the IPv4 network and a multicast address area to the IPv6 network compatible with IPv4 network;
• receiving an IPv6 multicast packet containing source and multicast destination addresses of the IPv6 network;
• and
• when a destination network of the IPv6 multicast packet is the IPv6 network connected to the IPv4 network, extracting source and multicast destination addresses of the IPv4 network from the source and multicast destination addresses contained in the IPv6 multicast packet, capsulating the IPv6 multicast packet into an IPv4 format to form an IPv4 format packet, and multicast-tunneling the IPv4 format packet to the IPv6 network through the IPv4 network by referring to the multicast table.

A tunneling apparatus for multicasting between networks having different address formats, said apparatus comprising:

• a packet transmitter/receiver connected to a first network having a first address format and to a second network having a second address format for receiving and transmitting a packet, the second address format being different from the first address format;
• a multicast information manager for setting a multicast table containing information about receive and transmit interfaces in a multicast delivery tree structure for each of the first network and the second network;
• a capsulator/decapsulator for capsulating a packet received from the second network into a packet for the first network, and for decapsulating a packet received from the first network into a packet for the second network;
• and
• a multicast manager for assigning a multicast address area to the first network and a multicast address area to the second network compatible with the first network, for extracting source and multicast destination addresses in the first address format from source and multicast destination addresses in the second address format contained in a second network multicast packet for multicast-tunneling through the first network to the second network, and for multicast-tunneling the second network multicast packet to the second network through the first network by referring to the multicast table.

A tunneling apparatus for multicasting between an IPv4 network and an IPv6 network, said apparatus comprising:

• a packet transmitter/receiver connected to the IPv4 network and to the IPv6 network for receiving and transmitting a packet;
• a multicast information manager for setting a multicast table containing information about receive and transmit interfaces in a multicast delivery tree structure for each of the IPv4 network and the IPv6 network;
• a capsulator/decapsulator for capsulating a packet in an IPv6 network format into a packet in an IPv4 network format, and for decapsulating the capsulated packet in the IPv4 network format into the packet in the IPv6 network format;
• and
• a multicast manager for assigning a multicast address area to the IPv4 network and a multicast address area to the IPv6 network compatible with IPv4 network, for extracting source and multicast destination addresses in an IPv4 address format from source and multicast destination addresses in an IPv6 address format contained in an IPv6 multicast packet for multicast-tunneling through the IPv4 network to the IPv6 network, and for multicast-tunneling the IPv6 network multicast packet to the IPv6 network through the IPv4 network by referring to the multicast table.