A method is disclosed for assisting a handover of a data session from a first routing path, associated with a first access network, to an alternative routing path, associated with an alternative access network. Data is routed over the first access network to a UT by binding a session identifier to a first routing identifier. The session identifier and the first routing identifier are defined in accordance with a standard protocol routing scheme of the first access network. The method comprises receiving a capability message uniquely identifying the UT according to both a standard protocol routing scheme of said first access network, and an alternative standard protocol routing scheme of said alternative access network. The method further comprises creating an alternative routing identifier complying with the alternative standard protocol routing scheme, associating the alternative routing identifier with the UT, and associating the session identifier with the alternative routing identifier.