Patent ID: 7639702

Claim:
A plug-in card for an optical transmission apparatus, the plug-in card comprising: a POH inserting unit that inserts a path overhead byte including J1 byte data and B3 byte data into input data; a J1 byte generating unit that generates J1 byte data for the path overhead byte to send the generated J1 byte data to the POH inserting unit, and that sends information on the J1 byte data to a second plug-in card operating at a spare side in a redundant structure when the plug-in card operates as an on-use side plug-in card, the J1 byte generating unit receiving information on J1 byte data from the second plug-in card operating at the on-use side in the redundant structure, the information being used by the plug-in card at the on-use side, to match spare side J1 byte data to on-use side J1 byte data on the basis of the information, and sending the matched J1 byte data to the POH inserting unit when the plug-in card operates as a spare side plug-in card; and a B3 byte calculating unit that generates B3 byte data for the path overhead to send the generated B3 byte data to the POH inserting unit, and that sends information on the B3 byte data to the second plug-in card operating at the spare side when the plug-in card operates as the on-use side plug-in card, the B3 byte calculating unit receiving information on B3 byte data from the second plug-in card operating at the on-use side, the information being used by the plug-in card at the on-use side, to match spare side B3 byte data to on-use side B3 byte data on the basis of the information, and sending the matched B3 byte data to the POH inserting unit when the plug-in card operates as the spare side plug-in card.