Patent attributes
A communication control system comprising a plurality of user terminals connected via a network composed of a plurality of sub networks; and a home agent managing the addresses of the plurality of user terminals. The home agent stores the care-of addresses of the plurality of user terminals, which are associated with one home address, in a user data storage unit. When update information including a care-of address is received from the predetermined user terminal, the home agent finds a sub network to which the predetermined user terminal is connected based on the update information, references the user data storage unit to determine the care-off address of an appropriate user terminal that is one of user terminals connected to the sub network, and transfers information, which is sent to the home address, to the determined care-of address.