Patent ID: 7535870

Claim:
A method of forwarding IP packets, sent to an old care-of-address of a mobile node, following a handover of the mobile node from a first access router to a second access router, the method comprising: prior to completion of said handover, providing said first access router or proxy node with information necessary to determine a new IP care-of-address to be used by the mobile node when the mobile node is transferred to the second access router; at said first access router or said proxy node, determining the new care-of-address for the mobile node using said information, and confirming ownership of the new care-of-address by the mobile node by; using the public key of a public-private key pair belonging to the mobile node to generate the new care-of-address. generating a signed message at the mobile node with the private key, and sending that signed message to the first access router; and subsequently forwarding packets received at said first access network and destined for said old care-of-address, to the new care-of-address, wherein the second access router verifies the relevance of tunnel set-up requests by periodically sending a nonce to listening mobile nodes, said mobile node hearing this nonce when the mobile node scans for a new link and including the nonce in the mobile node's notification to the first access router, the first access router including the nonce in the tunnel set-up message.