Method and network unit for setting up a connection in a second network (16) from a first user terminal (21) to a second user terminal (22), when a connection in a first network (15) is present between the first user terminal (21) and at least the second user terminal (22). The connection in the second network (16) is initiated using a context dependent second network address, the context dependent second network address identifying a combinational service in the second network (16). The combinational service comprises retrieving the second network address of the second terminal (22) using a common part (17) of the first and second network (15, 16), and completing the set up of the second connection using the second network address of the second terminal (22).