Apparatus for and methods 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 are disclosed. The gateway node is configured to select the first channel from a plurality of channels configured to transfer data packets to the destination packet data protocol address of the correspondent node, wherein the data packet is sent from a mobile node of a second packet-switched data network external to the first network, and 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.