The controller then updates the flow table entries at the SDN switch and a new flow table entry called as advertised window (awnd) is added which represents the new calculated sending rate.
where [awnd.sub.r] = value of awnd of TCP ACK packet arriving at the switch [awnd.sub.i] = value of awnd in the flow table for the i-th elephant flow
where the average value of awnd, [awnd.sub.avg], can be calculated by
Meanwhile, assuming the observed values of awnd are ([awnd.sub.1], [awnd.sub.2], ..., [awnd.sub.m]), the values of [awnd.sub.max] and [awnd.sub.min] can be computed by [awnd.sub.max] =([awnd.sub.1], [awnd.sub.2], ..., [awnd.sub.m]) and [MATHEMATICAL EXPRESSION NOT REPRODUCIBLE IN ASCII]
Policing of TCP traffic can be performed using classical methods such as priority queues and traffic shaping, or by instrumenting TCP packets to manipulate receiver's advertised window (awnd).
Queuing delay increases linearly until the number of packets reaches to min(awnd, cwnd).
In addition, even if the receiver buffer is full of out-of-sequence packets, buffer overflow due to the expanded cwnd may be prevented as the buffer of the TCP receiver is flow-controlled by means of advertised window (awnd