Which traffic descriptor is used for marking？ （）

单项选择题WhichheaderorsetofheadersdoesCRTPcompress？（）

A.Layer 2
B.Layer 3
C.Layer 4
D.Layer 2 and Layer 3
E.Layer 3 and Layer 4

多项选择题Whatarethethreeelementsofconfiguringcongestionmanagement？（）

A.queue creation
B.determining packet drop thresholds
C.determining the random early detection method
D.traffic classification
E.queue scheduling
F.FIFO configuration

多项选择题Whichtwostatementsaretrueabouttrafficshapingandtrafficpolicing？（）

A.both traffic shaping and traffic policing cause retransmissions of connection-oriented protocols such as TCP
B.both traffic shaping and traffic policing support the marking and re-marking of traffic
C.the effects of traffic shaping and traffic policing when configured on a router are applied to outgoing traffic
D.traffic shaping queues excess traffic whereas traffic policing discards excess traffic
E.traffic shaping allows the traffic to exceed the bit rate whereas traffic policing prevents the traffic from exceeding the bit rate

单项选择题WhatisthegoalofQoSinanetwork？（）

A.prevent packets from being dropped
B.increase available bandwidth
C.reduce hardware errors
D.provide predictable network service
E.eliminate propagation delay
F.eliminate jitter and packet loss

单项选择题WhatarethestepsforconfiguringstatefulNBARfordynamicprotocols？（）

A.use the command ip nbar protocol-discovery to allow identification of stateful protocols. Use the command ip nbar port-map to attach the protocols to an interface
B.use the command match protocol rtp to allow identification of real-time audio and video traffic. Use the command ip nbar port-map to extend the NBAR functionality for well-known protocols to new port numbers
C.use the command match protocol to allow identification of stateful protocols. Use the command ip nbar port-map to attach the protocols to an interface
D.configure a traffic class. Configure a traffic policy. Attach the traffic policy to an interface. 
E.configure video streaming. Configure audio streaming. Attach the codec to an interface