System and method for supporting the transfer of internet data packets when a mobile node roams from a home network to a visited network

摘要

A packet data gateway of a home packet data network is operable to communicate internet packets to and from a mobile node using an internet protocol, and to provide a communications session to the mobile node, when the mobile node is affiliated with the home packet data network, the home packet data network including a home agent of the mobile node. Upon receipt of a binding update internet packet providing a care of address of the mobile node following a change of affiliation from the home packet data network to a visited packet data network, said visited packet data network being operable to communicate internet packets to and from the mobile node to provide the communications session, when the mobile node is affiliated with the visited packet data network, the packet data gateway and the mobile node are operable to establish a mobile internet protocol tunnel for communicating internet packets to and from the mobile node in the visited network from and to the packet data gateway and to establish an internet protocol security tunnel, the mobile internet protocol tunnel being arranged to be within the internet protocol security tunnel.