单选题Refer to the exhibit. Which statement is true about a voice VLAN？（）A  Physically the voice network and the data network are separate.B  The voice traffic will normally be on a different IP subnet than will the data traffic.C  End user intervention i

第1题：

Which statement is true about the comparison of voice traffic with video traffic？（）

• 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、 Voice 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.

第2题：

Which two statements are true about voice VLANs？（）

• A、Voice VLANs are only used when connecting an IP phone and a host to distinct switch ports
• B、Access ports that are configured with voice VLANs will always trust the CoS that is received from IP phones
• C、Access ports that are configured with voice VLANs may or may not override the CoS value that is received from an IP phone
• D、Voice VLANs are configured using the switchport voice vlan vlan-ID interface configuration command
• E、Voice VLANs provide a trunking interface between an IP phone and an access port on a switch to allow traffic from multiple devices that are connected to the port
• F、Enabling Voice VLAN on a switch port will automatically configure the port to trust the incoming CoS markings

第3题：

Which three statements are true about the data traffic characteristics of voice traffic？ （）

• A、latency must be kept below 150 ms
• B、latency is not a concern as long as jitter is kept below 30 ms
• C、voice packets do not require a specific type of queuing
• D、voice packets are rather small
• E、voice packets require TCP for rapid retransmission of dropped packets
• F、voice packets require a fairly constant bandwidth reserved for voice control traffic as well as forthe voice payload

第4题：

Which statement is true about the comparison of voice traffic with video traffic？（）

• 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

第5题：

VOIP has been implemented at the main office of the Company network. Which two statements  are true about voice packets in a LAN？（）

• A、 Voice carrier stream utilizes Real-Time Transport Protocol (RTP) to carry the audio/media  portion of the VoIP communication.  
• B、 Voice traffic data flow involves large volumes of large packets.  
• C、 Because a packet loss involves a small amount of data, voice traffic is less affected by packet  losses than traditional data traffic is.  
• D、 Voice packets are encapsulated in TCP segments to allow for proper sequencing during  delivery. 
• E、 Voice packets are very sensitive to delay and jitter. 

第6题：

What does the interface subcommand switchport voice vlan 222 indicate？（）

• A、The port is configured for both data and voice traffic.
• B、The port is fully dedicated to forwarding voice traffic.
• C、The port will operate as an FXS telephony port.
• D、Voice traffic will be redirected to VLAN 222.

第7题：

You need to configure a new Company Catalyst 3560 switch for a VOIP-enabled office.  Which  three statements are true about the voice VLAN feature on this switch？（）

• A、The default CoS value for incoming traffic is set up to 0.
• B、The CoS value is trusted for 802.1p or 802.1q tagged traffic.
• C、PortFast is automatically disabled when a voice VLAN is configured.
• D、The voice VLAN feature is disabled by default.
• E、The IP phone accepts the priority of all tagged and untagged traffic and sets the CoS value to 4.
• F、When the voice VLAN feature is enabled， all untagged traffic is sent according to the default  CoS priority of the port

第8题：

Which two statements are true about voice packets in a LAN？ （Choose two.）  （）

• A、 Voice traffic data flow involves large volumes of large packets.
• B、 Because a packet loss involves a small amount of data， voice traffic is less affected by packet losses than traditional data traffic is.
• C、 Voice carrier stream utilizes Real-Time Transport Protocol （RTP） to carry the audio/media portion of VoIP communication.
• D、 Voice packets are very sensitive to delay and jitter.
• E、 Voice packets are encapsulated in TCP segments to allow for proper sequencing during delivery.

第9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10题：

Why is QoS important in a converged network?（）

• A、Because data does not need to arrive intact, so data transfer rates can be variable
• B、Because lost voice-data packets must be retransmitted
• C、Because voice data packets should arrive quickly and sequentially, and with no lost data
• D、Because voice data packets must follow a single dedicated path through the network