US Patent 7730238 Buffer management method and system with two thresholds

A method comprises providing a free buffer pool in a memory including a non-negative number of free buffers that are not allocated to a queue for buffering data. A request is received to add one of the free buffers to the queue. One of the free buffers is allocated to the queue in response to the request, if the queue has fewer than a first predetermined number of buffers associated with a session type of the queue. One of the free buffers is allocated to the queue, if a number of buffers in the queue is at least as large as the first predetermined number and less than a second predetermined number associated with the session type, and the number of free buffers is greater than zero.