| 摘要 |
<p>PROBLEM TO BE SOLVED: To prevent the cell output control of a preceding stage switch in a congested line from affecting the delay characteristics and abandonment rate characteristics of other non-congested lines. SOLUTION: When a cell arrives at a selected cell abandonment circuit 24, first whether or not selected cell abandonment request signals are originated from a queue length monitoring circuit 20 is confirmed. When a selected cell abandonment request is issued a connection number is checked of the VPI area and VCI area of the arrival cell, and whether or not an output line for which the connection number is heated is congested is retrieved of the congestion condition area of a congestion connection table 22. If it is not a connection heated for the congested line, the cell is made to pass through and inputted to a cell buffer 2. If it is a cell heated for the congested line, the cell is abandoned and made into a free celled. Also, when the selected cell abandonment request is not issued, whether or not the entire input cell abandonment request signals have been issued from the queue length monitoring circuit 20 is checked. If the entire input cell abandonment request is issued, the cell is abandoned and made into a idle cell. If the entire input cell abandonment request has not been issued, the cell is made to pass through and inputted to the cell buffer 2.</p> |
