A method for allocating space among a plurality of queues in a buffer includes sorting all the queues of the buffer according to size, thereby to establish a sorted order of the queues. At least one group of the queues is selected, consisting of a given number of the queues in accordance with the sorted order. A portion of the space in the buffer is allocated to the group, responsive to the number of the queues in the group. A data packet is accepted into one of the queues in the group responsive to whether the data packet will cause the space occupied in the buffer by the queues in the group to exceed the allocated portion of the space.