DYNAMIC BUFFER SUPERVISING SYSTEM FOR A DATA LINK ACCESS PROTOCOL CONTROL

In a communication apparatus of the type performing ISDN LAPD signal processing, the assignment of buffers each for temporarily storing a received data signal is supervised. Idle buffers are reserved in a common idle buffer pool while transmit buffers and receive buffers are supervised for each of service access points. The number of buffers awaiting processing or transmission is monitored at each predetermined period, on the identifier basis. As the number of idle buffers reserved in the idle buffer pool decreases to less than a predetermined value, the idle buffer assignment allowable for processing is restricted in number on the service access point basis and in matching relation to a function of the current number of waiting buffers and a predetermined threshold value. The restriction may be provided with a plurality of different levels, in which case a restriction level border value for a transition in a restriction tightening direction is selected to be smaller than that for a transition in a restriction relaxing direction with respect to the number of idle buffers. The number of idle buffers and the restriction level border value may be defined per unit time each.