A subscriber of a telecommunication system has a plurality of associated telecommunication devices which are each contactable via a device-shared identification address. A first device can communicate with a telecommunications network. A second device can communicate with a packet-switched network and a circuit-switched network. A control system receives an incoming telecommunication request associated with an incoming telecommunication request directed to the address, which has been routed to the control system based on the address. A first control phase is initiated where a first outgoing telecommunication request is transmitted over the telecommunications network to the first device and an operation is performed to at least attempt to transmit a second outgoing telecommunication request over the packet-switched network to the second device. If the operation is deemed to be unsuccessful, a second control phase is initiated where a third outgoing telecommunication request is transmitted over the circuit-switched network to the second device.