Patent ID: 8345606

Claim:
A method of enabling a gateway node of a first packet-switched data network to select a first channel for transferring a data packet to a destination packet data protocol address of a correspondent node provided service in the first network, wherein the gateway node is configured to select the first channel from a plurality of channels each configured to transfer data packets to the destination packet data protocol address of the correspondent node, wherein the data packet has been sent from a mobile node of a second packet-switched data network external to the first network, wherein the mobile node has been in a communication session with the correspondent node while provided service in a third packet-switched data network different to the second network, wherein mobility of the mobile node between networks or subnetworks is supported using the Mobile Internet Protocol (MIP) standards, the mobile node having a home packet data protocol address (HAddr) in the third network, the mobile node having moved to the second network and having been provided with a current packet data protocol address (CoA, CoCoA) in the second network, the method comprising: a) the mobile node sending a MIP correspondent binding update packet addressed to the correspondent node, wherein the home packet data protocol address of the mobile node is associated with the MIP correspondent binding update packet; b) the gateway node receiving the correspondent binding update packet and transferring it to the correspondent node using a second channel having no associated data packet filters; c) the correspondent node matching the home packet data protocol address of the mobile node associated with the correspondent binding update packet to the communication session with the mobile node; and d) in response to the matching, the correspondent node arranging for the current packet data protocol address of the mobile node to be included in the first data packet filter, wherein the first packet filter was created, prior to step d), so as to enable the gateway node to select the first channel for transferring data packets sent by the mobile node while involved in the communication session, and, in step d), the first data packet filter is modified to include the current packet data protocol address of the mobile node.