Mobile internet protocol system and route optimization method therefor

A communication optimization method for communicating through the Internet, the method comprising:

• providing a domain name to a mobile host;
• storing in a database a care-of address to correspond to the domain name of the mobile host, said storing being performed by a home agent when the care-of address of the mobile host is received, the care-of address corresponding to a new point of attachment when the mobile host attaches to the Internet from the new point of attachment;
• sending the care-of address corresponding to the domain name of the mobile host together with caching prevention information to a correspondent node by the home agent in response to a query about the mobile host by domain name from the correspondent node, the caching prevention information being set to prevent the correspondent node from caching the care-of address of the mobile host, the caching prevention information being set to prevent any domain name server from caching the care-of address of the mobile host;
• and
• communicating with the mobile host by the correspondent node using the care-of address corresponding to the domain name of the mobile host.

A mobile Internet Protocol system, comprising:

• an Internet;
• a mobile host having a domain name and establishing a link with the Internet;
• a home agent in a home network, said mobile host attaching to the Internet through said home agent when said mobile host is in the home network;
• and
• a foreign agent in a foreign network, said mobile host attaching to the Internet through said foreign agent when said mobile host is moved from the home network to the foreign network;
• said home agent storing in a domain name server database a care-of address of said mobile host to correspond to the domain name when said mobile host is attached to the Internet through said foreign agent, said home agent storing the care-of address in response to a registration request message sent to said home agent when said mobile host is moved to the foreign network, the registration request message containing the care-of address;
• said home agent sending to a correspondent node the care-of address and caching prevention information in response to a query from the correspondent node about said mobile host, the query being by domain name, the caching prevention information being set to prevent the correspondent node from caching the care-of address of the mobile host, the caching prevention information being set to prevent any domain name server from caching the care-of address of said mobile host.