Mobile IP route optimisation in IP protocol version transition scenarios

摘要

The invention relates to a method for routing packets in a system of packet-switched networks using different internet protocol versions. The system comprises a plurality of home agents, at least one mobile node and at least one correspondent node. A first mobile node is configured with at least one topologically correct internet protocol address of a first internet protocol version and is located in a network supporting at least routing of packets having a header of the first internet protocol version. The method comprises the following steps. Communication is requested with a first correspondent node being configured with at least an internet protocol address of a second internet protocol version and being located in a network supporting at least the routing of packets having a header of the second internet protocol version, by an application on the first mobile node. A first of the plurality of home agents is located in proximity to a direct path between the first mobile node and the first correspondent node, the first home agent being located in a network supporting at least the routing of packets to the first mobile node with the packets having a header of the first internet protocol version and the routing of packets to the first correspondent node with the packets having a header of the second internet protocol version. Bootstrapping is carried out with the first home agent to obtain a first home address of the second internet protocol version and other communication parameters. The first mobile node's location is registered with the first home agent by sending a first binding update message comprising a first mobile node's topologically correct address of the first internet protocol version as care-of address and the first home address as home address; and the first home agent is used in bi-directional tunnelling mode, the outer header of the tunnelled packets using the first internet protocol version and the inner header of the tunnelled packets using the second internet protocol version, for communication with the first correspondent node, with the communication parameters set up in the bootstrapping step and the first home address as home address.