A.synchronizes FIFO， PQ， CQ， and MDRR， with WFQ， CBWFQ， and LLQ
B.enables strict priority queuing for voice traffic， and weighted round robin queuing for data traffic
C.enables low latency queuing to ensure that voice traffic receives priority treatment
D.enforces a trust boundary on switch access ports and uplinks/downlinks 
E.modifies queue sizes as well as queue weights where required 
F.adjusts link speeds to adapt to QoS needs

A.class-based policing is configured using the Modular QoS command-line （MQC）
B.only the Frame Relay traffic-shaping （FRTS） mechanism can interact with a Frame Relay network， adapting to indications of Layer2 congestion in the WAN links
C.Distributed Traffic Shaping （DTS） is configured with the police command under the policy map configuration
D.both Frame Relay traffic shaping （FRTS） and virtual IP （VIP）-based Distributed Traffic Shaping （DTS） have the ability to mark traffic

A.serialization delay
B.end-to-end delay
C.lack of bandwidth
D.inconsistent port costs
E.routing table convergence issues
F.poor file transfer rates

A.video conferencing traffic tends to be much more bursty in nature and is more prone to have an impact on other traffic flows
B.latency requirements are less stringent for video traffic than for voice traffic
C.video traffic is less sensitive to dropped packets than for voice traffic
D.video traffic requires the retransmission capabilities of TCP whereas voice uses UDP
E.video traffic tends to be much more bursty in nature and is more prone to have an impact on other traffic flows
F.voice traffic requires the retransmission capabilities of TCP whereas video uses UDP

A.the two steps of digital to analog conversion are decompression and reconstruction of the analog signal
B.the two steps of digital to analog conversion are decoding and filtering
C.the two steps of digital to analog conversion are decompression and filtering of the analog signal
D.the two steps of digital to analog conversion are quantization and decoding