The invention relates to optimizing a data path between two communication nodes. A route optimization agent (ROA) is determined in the current network of the second communication node, preferably on the data path between the two communication nodes. Then, an IP tunnel is established between the first communication node and the ROA, the IP tunnel and the corresponding security association of said IP tunnel being based on the home address of the first communication node in its home network. The first communication node may have two IP tunnels based on the same home address, one to its home agent and one to the ROA. Corresponding routing entries and binding cache entries need to be established in the ROA and the first communication node so that all data packets between the two communication nodes are exchanged via the established IP tunnel over the ROA.