US Patent 7912375 Optical transceiver

An optical transceiver performs an optical transmitting and receiving operation, and has a first memory and an external interface. The external interface receives information from a host device and writes the received information in the first memory. The external interface reads the information from the first memory in response to an external command and transfers externally the read information. The information includes at least one of an operation start date, when the optical transceiver starts the optical transmitting and receiving operation, and an operation termination date, when the optical transceiver terminates the optical transmitting and receiving operation.