ATM communication apparatus and ATM cell forwarding control method

An ATM (Asynchronous Transfer Mode) communication apparatus which is connected to a plurality of input lines and a plurality of output lines and transmits a cell received from each of the input lines to one of the plurality of output lines, which is specified by connection identification information included in a header of the cell, comprising:

• a buffer memory for temporarily storing cells received from each of the input lines;
• a write control unit for writing the cells received from each of the input lines into the buffer memory so that cells stored in the buffer memory form cell queues corresponding to connections for each output line;
• a read control unit for reading out cells from each of cell queues formed in the buffer memory while guaranteeing a minimum cell rate predetermined for each connection within a range not exceeding a predetermined peak cell rate;
• and
• means for adding congestion indication to a cell read out from a cell queue of which stored cell amount exceeds a preset threshold.