An apparatus for enabling a first device to identify a second device comprises a first interface and a second interface. Each interface is configured to allow communication between the first device and the second device, and the first interface is distinct from the second interface. The apparatus further comprises one or more controllers configured to receive a first identifier from the second device via the first interface. If the first identifier has a predetermined value, the controllers receive a second identifier from the second device via the second interface. The controllers identify the second device using the second identifier.