ATM switching system with bandwidth control function

In the 21st century, 10∼30 Mbps video services will be the main traffic services of B-ISDN. Therefore, bandwidth control is effective for dividing a 150-Mbps line into the call bandwidths. A shared buffer-type ATM switch with this function can be achieved by queueing call by call and by reading out cells from the queues according to the bandwidth control table sequence. When the traffic is random with utilization of 0.9, the switch with 128∼512 queues on the 4000-cell shared buffer has sufficiently small cell loss characteristics. Multiqueueing technology is provided by embedded RAMs which point to the first addresses and last addresses of the queues. Queue length control, which limits each queue length, for multiqueueing is provided by the embedded RAMs. A one-board switch with 128 queues on a 4000-cell shared buffer is developed.