Combinational networks may provide simultaneous connectivity over networks of different type between User Equipment of an A-party and B-party. A communication session, comprising a circuit switched call and one or more packet switched sessions, may be deployed simultaneously over different network types, in relation to the same User Equipment. The circuit switched call and the packet switched session may be correlated. As to retrieve the packet switched address of a circuit switched call partner, a retrieval for a packet switched network address is initialized by means of a circuit switched protocol over a circuit switched network. The address retrieval request is directed to the call partner or a network node that accomplishes the network address request.