IP mobility

In a network, a node for forwarding IP packets sent to a mobile node via an old care-of-address of the mobile node, following a handover of the mobile node to another node, the node and the another node being a first access router and a second access router respectively, the node comprising:

• means in the node for determining a new care-of-address for the mobile node for when the mobile node is transferred to the another node prior to completion of said handover, the node assuming that the mobile node is stationary based on information from a proxy node acting as an Internet Protocol level proxy for the mobile node;
• receiving means for receiving a notification from the mobile node sending from a new link attached to the second node, the node confirming the timeliness of the notification prior to forwarding packets to the new care-of-address by using a nonce periodically sent by the node and echoed back in the notification;
• means in the node for confirming ownership of the new care-of-address by the mobile node;
• and
• subsequently forwarding packets received at said node, destined for said old care-of-address, to the new care-of-address.

In a packet switched data network, a mobile node for receiving forwarded IP packets, sent to an old care-of-address of the mobile node following a handover of the mobile node from a first access router to a second access router, the mobile node comprising:

• transmission means for:
• sending to said first access router, or a proxy node, information necessary to predict a new care-of-address prior to completion of said handover, to be used when the mobile node is transferred to the second access router wherein the new care-of-address is one of a plurality of care-of-addresses for receiving forwarded packets from the first access router;
• sending a notification to the first access router or the proxy node that the mobile node is preparing to move;
• and
• sending, from a new link attached to the second access router, to the node or the proxy node confirmation of timeliness of the notification prior to forwarding packets to the new care-of-address the confirmation including the nonce received from the second access router;
• receiver means for receiving the forwarded packets from the first access router at the new care-of-address, and
• detector means for detecting a nonce when scanning for a new link and including the nonce in a notification to the first access router, said nonce being received from the second access router.