Patent ID: 7720380

Claim:
An optical transmission apparatus in a ring transmission system having a plurality of optical transmission apparatuses via a bidirectional optical transmission path connected in a ring shape, said plurality of optical transmission apparatuses including an add node, which is an optical transmission apparatus for adding an optical signal, and a drop node, which is an optical transmission apparatus for dropping the optical signal from said add node, said optical transmission apparatus comprising: a storage unit to store an arrangement order information of the plurality of optical transmission apparatuses connected in the ring shape and identification information of each optical transmission apparatus; a squelch data link processing unit to receive, from optical transmission apparatus being located adjacent to one side, a first hop count, which is the number of optical transmission apparatuses being existent between to the add node, and receive, from optical transmission apparatus being located adjacent to the other side, a second hop count, which is the number of optical transmission apparatuses being existent between to the drop node, by using a squelch data link; and a squelch table generation unit to obtain the identification information of the add node based on the arrangement order information and the received first hop count, obtain the identification information of the drop node based on the arrangement order information and the received second hop count, and generate the squelch table storing the identification information of the add node and the drop node; wherein the squelch data link processing unit increments the received first hop count and transmits the incremented first hop count to the optical transmission apparatus being located adjacent to the other side, and also increments the received second hop count and transmits the incremented second hop count to the optical transmission apparatus being located adjacent to the one side.