Patent ID: 7609668

Claim:
A system for distributing packets for communication to a mobile unit comprising: a mobile unit having a device identifier and an internet protocol (IP) address comprising a first subnet identifier, the mobile unit roaming in a foreign network having a second subnet identifier; a mobility manager operable to determine a multicast address for the mobile unit based on the device identifier, to receive multicast address requests that include the device identifier, and to communicate the multicast address responsive to the multicast address requests; a plurality of foreign agents in the foreign network, the foreign agents operable to detect the mobile unit, to determine the device identifier for the mobile unit, to communicate a request including the device identifier to the mobility manager, to receive the multicast address from the mobility manager, and to register for a multicast group identified by the multicast address; and a home agent operable to receive IP packets addressed to the mobile unit, to determine the multicast address associated with the mobile unit, to encapsulate the IP packets as payloads for multicast packets addressed to the multicast address, and to communicate the multicast packets for receipt by said plurality of foreign agents registered for the multicast group using a packet network, wherein the home agent determines the multicast address by communicating a request including the IP address of the mobile unit to the mobility manager and receiving the multicast address from the mobility manager responsive to the request.