NAT system for supporting mobile IP in private networks and its method

摘要

A NAT system for supporting mobile IP in private networks and its method. A mobile node moves from its home network to a foreign private network and obtains a CoA from the private network. The mobile node sends a registration packet to a home agent in the home network. The registration packet has a swap address option field. A NAT device in the private network swaps the source address with the swap address of the registration packet, and translates the source address into the public address of the NAT device, thereby sending the registration packet to the home agent. After receiving the registration packet, the home agent responds a registration reply packet having a swap address option field filled in the CoA. The NAT device swaps the destination address with the swap address of the registration reply packet, thereby sending the registration reply packet to the mobile node.