A method of enabling dual registration of a User Equipment, UE, with first and second Internet Protocol Multimedia Subsystem, IMS, networks, the method comprising, in response to a connection request made to a gateway node by the UE, sending to the UE, network addresses of respective first and second Proxy Call Session Control Functions, P-CSCF, the first and second P-CSCFs being configured to enable IMS registrations to the first and second IMS networks respectively.