Abstract: A transmission apparatus includes a memory and a circuit. The memory store control data included in a frame received from outside the apparatus and state information indicating a state of the control data in the transmission apparatus in association with each other. The circuit records the control data included in the frame to the memory. The circuit changes the state information to information indicating that the recording of the control data is completed. The circuit determines whether or not the control data stored in the memory is to be rewritten. The circuit rewrites the control data stored in the memory, upon determining that the control data is rewritten. The circuit changes the state information to information indicating that the rewriting of the control data is completed. The circuit reads the control data stored in the memory.

Abstract: A SONET/SDH transmission apparatus comprises a plurality of interface units that accommodate a plurality of lines, and mesh wiring that interconnects the interface units in a mesh pattern. Each of the interface units includes a time slot interchange (TSI) unit to output a signal selected from among a plurality of signals through the TSI processing of a plurality of signals on the lines accommodated at all the interface units, a detection unit to detect alarm information on the lines accommodated at all the interface units, and a control unit to provide the TSI unit with control data reflecting protective switching operation calculated by computation of a logic circuit which virtually executes the protective switching operation to be as for the plurality of lines.

Abstract: A transmission apparatus includes a memory and a circuit. The memory store control data included in a frame received from outside the apparatus and state information indicating a state of the control data in the transmission apparatus in association with each other. The circuit records the control data included in the frame to the memory. The circuit changes the state information to information indicating that the recording of the control data is completed. The circuit determines whether or not the control data stored in the memory is to be rewritten. The circuit rewrites the control data stored in the memory, upon determining that the control data is rewritten. The circuit changes the state information to information indicating that the rewriting of the control data is completed. The circuit reads the control data stored in the memory.

Abstract: A SONET/SDH transmission apparatus comprises a plurality of interface units that accommodate a plurality of lines, and mesh wiring that interconnects the interface units in a mesh pattern. Each of the interface units includes a time slot interchange (TSI) unit to output a signal selected from among a plurality of signals through the TSI processing of a plurality of signals on the lines accommodated at all the interface units, a detection unit to detect alarm information on the lines accommodated at all the interface units, and a control unit to provide the TSI unit with control data reflecting protective switching operation calculated by computation of a logic circuit which virtually executes the protective switching operation to be as for the plurality of lines.