There is provided a method and a system for identifying or verifying the fiber arrangement and/or the cable type of multi-fiber array cables (such as MPO cables) which employs an OTDR acquisition device at the near end of the MPO cable, a loopback device at the far end and an array of signatures detectable by the OTDR, either at the far or the near end. The loopback device allows performing bidirectional OTDR measurements with a single OTDR acquisition device (without moving it from one end to the other) and the signature array provides fiber arrangement/cable type identification or verification.