Methods and apparatus for data transfer in a packet-switched data network

Abstract

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.

What is claimed is: 
     
         1 . 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, the gateway node being arranged to select the first channel from a plurality of channels each being for transferring data packets to the destination packet data protocol address of the correspondent node, the data packet having been sent from a mobile node of a second packet-switched data network external to the first network, the mobile node having been in a communication session with the correspondent node while provided service in a third packet-switched data network different to the second network, the method comprising:
 a) the mobile node associating, with the data packet, a first packet data protocol address which it used in the communication session with the correspondent node;   b) the gateway node selecting the first channel by matching the first packet data protocol address associated with the data packet received by the gateway node to a first data packet filter associated with the first channel.