Patent ID: 8005357

Claim:
An optical transmission apparatus for transmitting an optical SDH/SONET signal in a ring network, comprising: a first line card and a second line card, each including a hardware unit, a CPU, and an inter-hardware communicating unit, wherein the hardware unit obtains failure information on a redundant line including a working line and a protection line, the CPU determines switching control of the redundant line based on the failure information obtained by the hardware unit, and thereby the hardware unit switches the redundant line based on the switching control determined by the CPU, and the inter-hardware communicating unit communicates, from the hardware unit of one of the first line card and the second line card to the hardware unit of the other of the first line card and the second line card, the failure information obtained by the hardware of the one of the first line card and the second line card, wherein each of the first line card and the second line card further includes a CPU master-slave determining unit that determines, when a predetermined input section receives line setting information that the corresponding line card is an interface for the working line or the protection line, the CPU of the line card set as an interface for the protection line to be a master CPU, and the CPU of the line card set as an interface for the working line to be a slave CPU; a hardware master-slave setting unit that causes the CPU determined to be the master CPU by the CPU master-slave determining unit to set the hardware working under the master CPU to be master hardware, and the hardware working under the slave CPU to be slave hardware; and a switch controlling unit that causes the CPU determined to be the master CPU by the CPU master-slave determining unit to control the hardware set as the master hardware by the hardware master-slave setting unit to switch the redundant line.