A.Traffic bursts are smoothed out by queuing the excess traffic to produce a steadier flow of data
B.Excess traffic is buffered so that the traffic remains within the desired rate.
C.Packets that conform to traffic policies are not delayed.
D.Packet marking is available and allows excess packets to be re-marked with a lower priorit

A.Queuing introduces equal delays for packets of the same flow， resulting in jitter.
B.When congestion occurs， dropping affects most of the TCP sessions， which simultaneously back off and then restart again.
C.All buffers can temporarily be seized by aggressive flows， and normal TCP flows experience buffer starvation.
D.There is no differentiated drop mechanism. Higher priority traffic is dropped in the same way as best-effort traffic.
E.In TCP starvation， traffic exceeds the queue limit because of the bursty nature of packet networks. A router cannot handle multiple concurrent TCP sessions.
F.Global synchronization occurs because multiple TCP hosts reduce their transmission rates at random intervals in response to packet dropping