Which two QoS classification and marking statements are true？ （）A、 In a Frame Relay network， delay sensitive traffic is tagged with the discard eligible （DE） bit.B、 In an MPLS network， the three most significant bits of the DSCP or the IP precedence of th

第1题：

Which two QoS classification and marking statements are true？（）

• A、 In a Frame Relay network， delay sensitive traffic is tagged with the discard eligible （DE） bit.
• B、 In an MPLS network， the three most significant bits of the DSCP or the IP precedence of the IP packet are copied into the MPLS EXP field
• C、 In an MPLS network， the MPLS EXP bits are used to identify up to 16 CoS values.
• D、 The differentiated services code point （DSCP） field consists of the first three bits of the IP precedence field in the header of an IP packet.
• E、 The 802.10 standard uses a three bitfield referred to as the user priority bits （PRI） to mark packets as belonging to a specific CoS.

第2题：

You work as a network technician. Your boss is interested in the QoS technology in the context ofvideo traffic. What can be said of application of this technology in this type of network？（）

• A、The access layer is the initial point at which traffic enters the network. Traffic is marked （orremarked） at Layers 2 and 3 by the access switch as it enters the network， or is "trusted" that it isentering the network with the appropriate tag
• B、No traffic marking occurs at the core layer. Layer 2/3 QoS tags are trusted from distributionlayer switches and used to prioritize and queue the traffic as it traverses the core
• C、Traffic inbound from the access layer to the distribution layer can be trusted or reset dependingupon the ability of the access layer switches. Priority access into the core is provided based onLayer 3 QoS tags
• D、IP precedence， DSCP， QoS group， IP address， and ingress interface are Layer 2 characteristics that are set by the access layer as it passes traffic to the distribution layer. Thedistribution layer， once it has made a switching decision to the core layer， strips these off
• E、MAC address， Multiprotocol Label Switching （MPLS）； the ATM cell loss priority （CLP） bit， theFrame Relay discard eligible （DE） bit， and ingress interface are established by the voicesubmodule （distribution layer） as traffic passes to the core layer
• F、The distribution layer inspects a frame to see if it has exceeded a predefined rate of trafficwithin a certain time frame， which is typically a fixed number internal to the switch. If a frame isdetermined to be in excess of the predefined rate limit， the CoS value can be marked up in a waythat results in the packet being dropped

第3题：

Which three are characteristics of voice traffic in the Company VOIP campus network？（）

• A、TCP retransmits
• B、UDP priority
• C、Bursty
• D、Delay sensitive
• E、Greedy
• F、Drop sensitive

第4题：

Which three characteristics of the traffic flow are taken into consideration when the QoS-for-VPNs feature （QoS pre-classify） provides packet classification and applies appropriate QoS service on tunnel interfaces？（）

• A、IP precedence bits
• B、DSCP bits
• C、original port numbers
• D、DE bits
• E、source IP address
• F、destination IP address

第5题：

Which two statements are true about the application of QoS in a converged network？（）

• A、end-to-end network delay times that exceed 50 ms for real-time traffic are considered unacceptable
• B、end-to-end network delay times that exceed 250 ms for real-time traffic are considered unacceptable
• C、end-to-end network delay is not a factor as long as the  delay is consistent
• D、some packet loss can be corrected by codec algorithms
• E、RSVP handles voice packet retransmission
• F、fragmentation is a result of packet loss

第6题：

Which two statements about the QoS policy generation phase of the Cisco SDM QoS wizard are true？（）

• A、the SDM QoS wizard will create two real-time traffic classes to handle VoIP， voice signaling， and video packets
• B、the SDM QoS wizard will create three real-time traffic classes to handle VoIP， voice signaling， video， and video packets
• C、the SDM QoS wizard will create four real-time traffic classes to handle VoIP， voice signaling， video， and video streaming packets
• D、the SDM QoS wizard will create two business-critical traffic classes to handle transactional and  network management packets
• E、the SDM QoS wizard will create three business-critical traffic classes to handle transactional， network management， and routing packets
• F、the SDM QoS wizard will create four business-critical traffic classes to handle transactional， network management， routing， and best-effort packets

第7题：

Which two statements are true about network voice traffic？ （Choose two.）（）

• A、 Voice traffic is affected more by link speed than FTP traffic is.
• B、 Voice traffic is affected more by packet delays than FTP traffic is.
• C、 Voice streams involve larger packet sizes than most TCP network traffic involves.
• D、 Voice traffic is more sensitive to packet loss than TCP network traffic is.
• E、 Voice traffic requires QOS mechanisms only in heavily loaded network segments.

第8题：

You need to determine where the trust boundaries will be in a new Company VOIP design.  Which  two statements are true about these trust boundaries？（）

• A、Trust boundaries are configured in the core of the network to provide the most efficient  forwarding based upon QoS markings，
• B、Setting trust boundaries at the edge of the network allows intermediate hop devices to  administer QoS policies without detailed packet identification.
• C、Trust boundaries are used to determine which QoS mechanism will be applied to the traffic.  
• D、At the trust boundaries， the untrusted traffic will be marked with a new QoS value appropriate  for the policy in place at the point where the traffic entered the campus network.  
• E、Trust boundaries define the firewall rules for QoS admission into a network.

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第13题：

Which four of these statements are restrictions for Frame Relay PVC bundles with QoS support for IP and MPLS？ （）

• A、A PVC bundle will not come up unless all the precedence， DSCP， and EXP levels are configured in thebundle.
• B、A PVC bundle can perform precedence and DSCP matching at the same time
• C、A PVC bundle may contain no more than sixteen PVCs
• D、A PVC can be in only one PVC bundle
• E、A PVC bundle cannot perform precedence and DSCP matching at the same time.
• F、A PVC bundle may contain no more than eight PVCs.

第14题：

Which three statements about classification marking of traffic at Layer 2 are true？ （）

• 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

第15题：

Which two statements are true about RSVP and the InServ QoS model？（）

• A、a drawback of implementing RSVP is the requirement to migrate to a supporting routing protocol
• B、RSVP uses DSCP to signal QoS requirements to routers 
• C、RSVP is a routing protocol
• D、RSVP is an IP protocol that uses IP protocol ID 46， and TCP/UDP ports 3455
• E、RSVP specifically provides a level of service for rate-sensitive and delay-sensitive traffic
• F、the flow-based approach of RSVP is ideal for large， scalable implementations such as the public internet

第16题：

Which three statements about L2TPv3 are true？（）

• A、L2TPv3 Frame Relay support includes only 32-bit DLCI addressing
• B、L2TPv3 sessions do not support Frame Relay LMI interworking
• C、Multipoint DLCI is not supported
• D、To use DCE or a Network-to-Network Interface on a Frame Relay port， you must configure the frame-relay switching command
• E、L2TPv3 feature does not support Frame Relay extended addressing

第17题：

Which Cisco IOS traffic-shaping mechanism statement is true？ （）

• 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

第18题：

Which two statements are true about trust boundaries？（）

• A、Classifying and marking traffic should be done as close to the traffic source as possible. 
• B、Classifying and marking traffic should be done at the distribution layer.
• C、Traffic is classified and marked as it travels through the network.
• D、If untrusted traffic enters a switch， it can be marked with a new QoS value appropriate for the policy in place.
• E、The trust boundary moves depending on the type of traffic entering the network.

第19题：

You are the network administrator of an enterprise company that just deployed a global IP telephony environment. In order to guarantee good voice quality， you asked your provider to implement QoS on the CE routers of your MPLS network. On your LAN， you have also deployed QoS. Users， however， keep complaining about bad voice quality， and the provider does not see matches on the DSCP values that you have asked him to match upon. What is most likely the problem？（）

• A、The phones are not sending traffic with the correct DSCP value.
• B、The Cisco CallManager is not marking the traffic correctly.
• C、This is most likely a bug on the CE routers.
• D、Your LAN QoS is incorrectly configured.

第20题：

Which three statements are true about the appliance of QoS models？（）

• A、the DiffServ model requires applications to signal the network with QoS requirements
• B、the DiffServ model can be used to deliver QoS based upon IP precedence， or source and destination addresses
• C、the DiffServ model requires RSVP
• D、the best effort model is suitable for applications such as file transfer and e-mail
• E、the IntServ model requires applications to signal the network with QoS requirements
• F、the IntServ model model attempts to deliver a level of service based on the QoS specified by each packet

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