Abstract: A method and a system for monitoring the number of available buffers in a memory field. A signal indicative of the number of available buffers is provided to at least one comparator circuit and compared to at least one predetermined value representative of a limit on a range of numbers of available buffers, and previously stored in at least one D-latch circuit. An interrupt controller, responsive to the result of the comparison, outputs an interrupt signal to notify a microcomputer having an interrupt input port that the number of buffers is outside a range defined by the limit value.

Abstract: 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 a value which is less than a predetermined value, the idle buffer assignment allowable for processing is restricted in number on the service access point basis and in a matching relationship to a function of the current number of waiting buffers and a predetermined threshold value.