A.Asynchronous Transfer Mode （ATM）
B.data-link switching （DLSw）
C.Route Processor Redundancy （RPR）
D.Frame Relay （FR） 
E.Metro Ethernet
F.Multiprotocol Label Switching （MPLS）

A.a class can be identified as a single application， multiple applications with similar service needs，or be based on the source or destination IP address
B.a drawback of the DiffServ field in the MAC header to mark frames into behavior aggregates （BAs）
C.DiffServ uses the DiffServ field in the MAC header to mark frames into behavior
D.the DiffServ field occupies the same eight bits of the MAC header that were previously used for the ToS field
E.the first six high-order bits of the DiffServ field are used to identify the Resource Reservation Protocol （RSVP） value
F.the primary goal of DiffServ is scalability

A.FECN
B.LLQ
C.WRED
D.LFI
E.CRTP
F.CBWFQ

A.Cisco CallManager
B.Cisco CallManger Express （CME）
C.Cisco CallManager Gateway （CMG）
D.Cisco CallManager Voice Gateway （CMVG）
E.Media Gateway Control Protocol （MGCP）

A.increases link capacity
B.increases buffer space to accommodate bursts of traffic from delay-sensitive applications
C.provides prioritized forwarding for drop-sensitive applications
D.drop lower priority packets before congestion occurs
E.separates traffic into as many as 64 queues that can be uniquely prioritized

A.RTP multiplexing is used to keep multiple phone conversations separate
B.RTP provides end-to-end delivery services for voice traffic
C.UDP is used to ensure a reliable transmission from sender to receiver
D.RTP is used to provide resource reservation for the voice stream
E.UDP provides multiplexing

A.best-effort delivery
B.ingress committed rate （ICR）
C.shaping and policing
D.egress committed rate （ECR）
E.integrated Services （IntServ）
F.differentiated services （DiffServ）

A.data plane
B.control plane
C.service plane
D.management plane
E.hyper plane

A.determine a minimum bandwidth guarantee
B.determine interfaces to which to apply policy
C.assign priorities to the class
D.configure access control lists

A.a Frame Relay header includes a 1-bit discard eligible （DE） bit to provide the class of service （CoS）
B.an ATM header includes a 1-bit DE field to provide the CoS
C.an MPLS EXP field is inserted in the Layer 3 IP precedence field to identify the CoS
D.the CoS field only exists inside Ethernet frames when 802.1Q or Inter-Switch Link （ISL） trunking is used
E.in the IEEE 802.1p standard， three bits are used to identify the user priority bits for the CoS
F.in the IEEE 802.1q standard， six bits are used to identify the user priority bits for the CoS

A.G711
B.G726
C.G728
D.G729
E.G729A