In a communication system, a session control server receives a session request for User Equipment (UE) over a first network and exchanges signaling with the UE and a transfer control server to establish a media session. The transfer control server sends an association of the UE and the transfer control server to a translation server. The translation server associates the UE with the transfer control server. The translation server receives a transfer request for the UE from a second network and identifies the transfer control server associated with the UE. The translation server transfers the transfer request for delivery to the transfer control server. The transfer control server exchanges signaling with the second network responsive to the transfer request to transfer the media session for the UE from the first network to the second network.