Patent ID: 6868066

Claim:
An ATM (asynchronous transfer mode) cell transfer apparatus comprising: an input interface connected to a plurality of first transfer paths; a switch block having a plurality of input ports corresponding to said plurality of first transfer paths and a plurality of output ports; and an OAM cell processing hardware block having a memory unit, and wherein said input interface receives an SDH/SONET signal transferred to said input interface on one of said plurality of first transfer paths to output an input OAM cell corresponding to said SDH/SONET signal to one of said plurality of input ports of said switch block corresponding to the one of said first transfer paths on which said SDH/SONET signal is transferred, wherein said switch block receives said input OAM (operation and maintenance) cell at the one of said input ports, which acts as an OAM input port, said input OAM cell being output to said OAM cell processing hardware block together with a port number of said OAM input port, and receives at least one output OAM cell from said OAM cell processing hardware block, and wherein said OAM cell processing hardware block reads out said at least one output OAM cell corresponding to said input OAM cell from said memory unit based on said input OAM cell and said port number supplied from said switch block, and outputs said at least one output OAM cell to said switch block.