During voice implementation，  which two required items are configured at an access layer switch connected to an IP phone to provide VoIP communication？（）

A . a minimum of 48 kb/s B . a maximum of 48 kb/s C . a minimum of 48% of the available bandwidth D . a maximum of 48% of the available bandwidth

A . Voice VLAN的端口过滤模式可以分为安全模式和普通模式两种 B . 对于普通模式下，端口力口入Voice VLAN后设备不再检验报文的MAC地址 C . 安全模式下，设备将对每一个要进入Voice VLAN传输的报文都进行MAC匹配检査 D . 缺省情况下，Voice VLAN工作在普通模式

A . Voice VLAN的工作模式包含自动和手动两种 B . 自动模式下，系统会识别IP Phone发出的报文，如果匹配为语音报文，则将连接IP Phone的端口加入V.oice VLAN C . 手动模式下，需要手工将IP Phone加入Voice VLAN中 D . 手动模式下系统将不会向端口下发ACL

A . SCCAS B . PCRF C . PGW D . P-CSCF

A .  When the voice VLAN feature is enabled， all untagged traffic is sent according to the default  CoS priority of the port. B .  Enabling voice VLANs enables the switch to create multiple queues for traffic that is entering a  port. C .  When voice VLANs are configured on a trunk link， UplinkFast must also be enabled. D .  Voice VLANs are configured to enable the switch to forward frames marked with the proper  CoS values over separate physical links. E .  Enabling voice VLANs enables the switch to forward frames with a specific 802.1P marking.

A . DSL with 128k uplink /128k downlink B . cable with 256k uplink /256k downlink C . DSL with 128k uplink /768k downlink D . cable with 256k uplink /1.4M downlink

A . Increase the queue size of the voice class. B . Guarantee bandwidth during congestion to the voice class with a bandwidth command. C . Increase the tx-ring of the egress interface. D . Implement LLQ for the voice class. E . Decrease the rx-ring of the egress interface. F . Decrease the queue size of the voice class.

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 marking

A . provide far-end call control  B . provide far-end camera control  C . translate analog voice to packetized voice  D . transition call path between different networks  E . provide locations-based call admission control&e

A . 正确 B . 错误

A . 正确 B . 错误

A . average signal strength that is greater than -67 dBi B . cell overlap of 15 to 20 percent C . uneven wireless coverage D . absence of coverage hole

A . When the voice VLAN feature is enabled， all untagged voice and data traffic is sent through the voice VLAN. B . The voice VLAN feature is enabled by default. C . The IP phone overrides the priority of all incoming data traffic （tagged and untagged） and sets the CoS value to 0. D . The default CoS value is 1 for incoming voice and data traffic.

A . 地面正在通过VHF3 COM呼叫本飞机 B . VHF3正在进行话音通讯 C . 当前可进行数据传送 D . VHF3 COM只能进行话音通讯

A . 键上的ON灯点亮，表示莫尔斯码台识别信号被衰减 B . 键上的ON灯点亮，表示莫尔斯码台识别信号被增强 C . 键上的ON灯点亮，表示话音音频信号被衰减 D . 键上的ON灯点亮，表示话音音频信号被增强

A . Voice VLAN的工作模式包含自动和手动两种 B . 自动模式下，系统会识别IP Phone发出的报文，如果匹配为语音报文，则将连接IP Phone的端口加入Voice VLAN C . 手动模式下，需要手工将IP Phone加入Voice VLAN中 D . 手动模式下，系统将不会向端口下发ACL

A．VHF3收发机在话音方式下工作 B．数据链通讯中断 C．A+B