1. An apparatus for a communications network, the apparatus comprising: an interface circuit, wherein the interface circuit is configured to read frame data received from the communications network, the interface circuit is configured to write the frame data to be transmitted over the communications network, and the frame data comprises a plurality of transport overhead fields; and signature logic, wherein the signature logic is coupled to the interface circuit, the signature logic is configured to identify signature data, and the signature logic is configured to write the signature data into at least one of a plurality of transport overhead fields in an outgoing frame.