Patent ID: 7193977

Claim:
A hand-off notifying and controlling system, comprising: a mobile node (MN) that transmits a registration request message; a first foreign agent (FA) that provides a mobile internet protocol (IP) service to the MN, before a hand-off of the MN takes place; a second FA that provides the mobile IP service to the MN after the hand-off takes place; and a home agent (HA) that generates and transmits a registration release message to the first FA, upon receipt of the registration request message from the MN sent via the second FA directly to the HA, when the hand-off takes place, the HA setting the life time field of the registration release message to the value of 0 causing the first FA to delete prior registration information of the MN, stored in at least a visitor table, after receipt of the registration release message, wherein the registration release message has a data structure and type field value identical to the registration request message.