Abstract: A system for policing traffic of packet transfer in a hub. The system includes a first circuit and a second circuit and a first data line connecting the first circuit to the second circuit, wherein data is transmitted within and between the first circuit and the second circuit across said first data line. A second data line connects the first circuit to the second circuit, wherein data is transmitted within and between the first circuit and the second circuit across the second data line. A monitor monitors the first data line to determine when an amount of data being transmitted on the first data line within the first circuit has reached a threshold. A blocking mechanism prevents data from being transmitted on the first data line from the first circuit to the second circuit when the amount of data being transmitted on the first data line has reached the threshold.