In an apparatus, there are provided an IP transmitting and receiving unit for transmitting and receiving an IPv4 packet and an IPv6 packet; an IP header converting unit for performing a mutual conversion of the IPv4 packet and the IPv6 packet by an IP header conversion; a DNS substituting unit for receiving...http://www.google.de/patents/US6920138?utm_source=gb-gplus-sharePatent US6920138 - Communication method between IPv4 terminal and IPv6 terminal and IPv4-IPv6 converting apparatus
