Research on Mobile Communication in IPv4/v6 Mixed Networks

IETF has specified Mobile IPv4 and Mobile IPv6 in RFC3344 and RFC3775 respectively, but not yet discussed Mobile IPv4/v6 in any published RFC. This paper proposes a solution to Mobile IPv4/v6 problems and gives an example when Home Agent (HA) and Correspondent Node (CN) located in IPv4 network, Mobile Node (MN) moving in IPv4/v6 mixed networks. A gateway called Mobile IPv4/v6 translation gateway (MIPv4/v6-TG) is introduced to bridge between IPv4 network and IPv6 network, which is made up of a NAT-PT gateway and a Mobile IP application level gateway (MIP-ALG) built upon the NAT-PT gateway. On IPv4 side, MIPv4/v6-TG acts as one of the Mobile IPv4 entities to interact with other IPv4 entities under the specification of RFC3344. On IPv6 side, MIPv4/v6-TG acts as one of the Mobile IPv6 entities to interact with other IPv6 entities under the specification of RFC3775. Inside the gateway, Mobile IP related packets and messages received or sent by the entities that the gateway acts as are translated between Mobile IPv4 format and Mobile IPv6 format. In this way, the Mobile IP entities in IPv4 network and the Mobile IP entities in IPv6 network will be transparent to each other.