【单选题】
( )是以光纤为传输介质,并利用光波作为光载波传送信号的接入网,泛指本地交换机或远端交换模块与用户之间采用光纤通信或部分采用光纤通信的系统。___
A. 铜线接入
B. 网线接入
C. 光纤接入网
D. 同轴接入
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答案
C
解析
暂无解析
相关试题
【单选题】
接入网完成的诸多功能,下列哪一项不在其中( )。___
A. 交叉连接功能
B. 复用功能
C. 传输功能
D. 加密功能
【单选题】
( )不属于光纤的结构。___
A. 纤芯
B. 包层
C. 涂覆层
D. 松套管
【单选题】
( )不属于光纤通信优点。___
A. 损耗低
B. 容量大
C. 弯曲半径小
D. 抗电磁干扰性好
【单选题】
( )是目前宽带最宽的传输介质。___
A. 铜轴电缆
B. 双绞线
C. 电话线
D. 光纤
【单选题】
单模光纤1310nm衰减为( )。___
A. 1~1.2dB/km
B. 0.6~0.8dB/k
C. 0.8~1dB/km
D. 0.4~0.6dB/km
【单选题】
单模光纤1550nm衰减为( )。___
A. 0.4~0.5dB/km
B. 0.3~0.4dB/km
C. 0.2~0.3dB/km
D. 0.5~0.6dB/km
【单选题】
单模光纤与多模光纤相比较,单模光纤的纤芯直径相对较( ),在给定的工作波长上只能以单一模式传输,传输频带宽,传输容量( )。___
A. 细 大
B. 粗 大
C. 细 小
D. 粗 小
【单选题】
当光缆线路传输距离小于或等于5km时,其衰耗取( )dB___
A. 1
B. 2
C. 3
D. 4
【单选题】
光纤涂覆层的作用错误的有()。___
A. 增强光纤的强度
B. 色谱识别
C. 增加光纤的柔韧性
D. 反射光
【单选题】
目前光纤通信所用的波长( )。___
A. 1600nm~2400nm
B. 800nm~1600nm
C. 2400nm~3200nm
D. 3200nm~4000nm
【单选题】
下列传输介质中,哪种传输介质的抗干扰性最好?( )___
A. 双绞线
B. 光缆
C. 同轴电缆
D. 无线介质
【单选题】
下列的哪种光纤弯曲半径最小。( )___
A. G.652D
B. G.657B
C. G.652B
D. G.657A
【单选题】
下列哪种光纤接续方式损耗最小()___
A. 冷接
B. 活动连接
C. 快速连接
D. 熔接
【单选题】
下面哪个是光纤通信的缺点()___
A. 适应能力差
B. 原材料紧缺
C. 传输衰耗系数大
D. 弯曲半径不能过小
【单选题】
由于光纤中传输的光波比无线电通信使用的( )高得多,因此其通信容量就比无线电通信大得多。___
A. 频率
B. 幅度
C. 角度
D. 位移
【单选题】
以下宽带接入技术中,( )属于光纤接入?___
A. Wimax
B. xDSL
C. xPON
D. HFC
【单选题】
光纤是石英玻璃拉制成形,原材料来源丰富,并节约了大量有色金属。光纤弯曲半径不宜 ( ) ___
A. 过大
B. 过小
C. 采用固定弯曲半径
D. 无所谓
【单选题】
在( )波长处,单模光纤的材料色散和波导色散一为正、一为负,大小也正好相等。这就是说在这个波长处,单模光纤的总色散为零。该波长区就成了光纤通信的一个很理想的工作窗口,也是现在实用光纤通信系统的主要工作波段。___
A. 850nm
B. 1310nm
C. 1490nm
D. 1550nm
【单选题】
在光通信中,若光纤上承载的是波长为1490nm的光信号,每公里的损耗大概是:( )___
A. 0.18dB
B. 0.36dB
C. 0.72dB
D. 0.90dB
【单选题】
在光通信中,一个法兰盘的损耗大概是:( )___
A. 0.2db
B. 0.5db
C. 0.9db
D. 1.2db
【单选题】
家庭网关的PON口尾纤类型为( )___
A. FC
B. LC
C. SC
D. ST
【单选题】
光信号是以光功率来度量的,其单位是( )。___
A. Mw
B. dB
C. dBm
D. dBW
【单选题】
FTTB是指( )___
A. 光纤到大楼
B. 光纤到路边
C. 光纤到用户
D. 光纤到交接箱
【单选题】
有关OLT说法错误的是( )___
A. 向ONU以广播方式发送以太网数据
B. 发起并控制测距过程,但不记录测距信息
C. 发起并控制ONU功率控制
D. 为ONU分配带宽
【单选题】
有关ONU说法错误的是( )___
A. 选择接收OLT发送的广播数据
B. 响应OLT发出的测距及功率控制命令,并作相应的调整
C. 不对用户的以太网数据进行缓存,直接在OLT分配的发送窗口中向上行方向发送
D. 其它相关的以太网功能
【单选题】
EPON下行帧结构的特点错误的是( )___
A. 下行帧是一个复合帧
B. 下行帧包含多个变长数据包和同步标签
C. 每一个变长数据包是对应每一个特定地址的ONU的
D. 每一个数据包都包含变长数据包以及校验码几部分
【单选题】
有关EPON ONU测距说法错误的是( )___
A. 在注册过程中,OLT对新加入的ONU启动测距过程OLT使用RTT来调整每个ONU的授权时间
B. OLT也可以在任何收到MPCP PDU的时候启动测距功能
C. 在EPON系统中,解决ONU的注册冲突的方案有两种:随机延迟时间法和随机跳过开窗法
D. 以上都不对
【单选题】
对于EPON下带的窄带业务,如果voip使用H248协议,则如果网络状况不好,有丢包现象,那么传输模式推荐使用( )___
A. 全控T30方式
B. 自协商T30方式
C. 全控T38方式
D. 自协商T38方式
【单选题】
EPON在OLT和ONU之间规定了一种控制机制是( )___
A. CRC
B. FCS
C. LLID
D. MPCP
【单选题】
EPON 在软交换网络中属于哪一层?( )___
A. 业务层
B. 边缘层
C. 控制层
D. 核心层
【单选题】
ONU的认证是针对PON板上的端口的,如果ONU更换了连接OLT上的PON口,需要( )。___
A. 重启OLT
B. 无需任何操作
C. 删除原PON口后重新认证
D. 不能更换
【单选题】
XPON系统中,不属于应用层协议子系统的协议是( )___
A. DHCP
B. FTP
C. UDP
D. SNMP
【单选题】
在PON系统中,如果要传输CATV信号,采用的波长是( )。___
A. 1310nm
B. 1490nm
C. 1550nm
D. 850nm
【单选题】
PON技术采用的拓扑结构是( )。___
A. P2P
B. P2MP
C. MP2MP
D. MP2P
【单选题】
GPON中利用( )来标识每个业务流的。___
A. LLID
B. VLAN
C. GEMPORT
D. T-CONT
【单选题】
PON系统中的ONU设备位于OSI 7层模型的哪一层?( )___
A. 物理层
B. 数据链路层
C. 网络层
D. 传输层
【单选题】
GPON系统中采用强制( )传输方式。 ___
A. 单纤单向
B. 双纤双向
C. 双纤单向
D. 单纤双向
【单选题】
GPON ONU的最大发送光功率是多少( )___
A. +0.5db
B. -1 db
C. +5 db
D. +2 db
【单选题】
GPON将业务带宽分配方式分成4种类型,优先级从高到低分别是( ) ___
A. 保证带宽、固定带宽、非保证带宽和尽力而为带宽
B. 固定带宽、保证带宽、非保证带宽和尽力而为带宽
C. 固定带宽、保证带宽、尽力而为带宽和非保证带宽
D. 保证带宽、非保证带宽、固定带宽和尽力而为带宽
【单选题】
下列对EPON速率描述正确的是: ( )___
A. 上行155M / 下行 622M
B. 上行2.5G / 下行 2.5G
C. 上行1.244G / 下行 2.488G
D. 上行1.25G / 下行 1.25G
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Which three design requirements must be satisfied to enable RAID-6 objects in a VMware vSAN cluster? (Choose three.)___
A. vSAN Advanced license or higher
B. vSAN stretched cluster
C. at least six hosts contributing storage
D. deduplication and compression
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【多选题】
When using "Cluster resource percentage" for host failover capacity in vSphere HA Admission Control, the total resource requirements are calculated from which two values? (Choose two.)___
A. Total vCPUs assigned to each VM.
B. Average CPU usage on each VM over time.
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F. CPU reservations on each VM.
【多选题】
Which are four attributes of the Active vCenter HA node? (Choose four)___
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B. It constantly replicates vPostgres data with the Witness node.
C. It uses a public IP address for the management interface.
D. It runs the active vCenter Server Appliance instance.
E. It uses the vCenter HA network for replication of data to the Passive node.
F. It provides a quorum to protect against split-brain situations.
【多选题】
Which are two vCenter Server two-factor authentication methods? (Choose two.)___
A. RSA SecurID
B. Smart Card
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【多选题】
An administrator is creating VMkernel adapters on an ESXi 6.5 host and wants to create separate VMkernel adapters for every type of traffic in the default TCP/IP stack. Which three types of traffic can be explicitly enabled on a separate VMkernel adapter? (Choose three.)___
A. Virtual SAN traffic
B. NFS traffic
C. vMotion traffic
D. vSphere HA traffic
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【多选题】
When migrating a Windows vCenter Server 6.0 to the vCenter Server Appliance 6.5, which two will be migrated by default? (Choose two.)___
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B. Configuration
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【多选题】
Which three types of Content Libraries exist within vSphere 6.5? (Choose three.)___
A. Remote Content Library
B. Published Content Library
C. Local Content Library
D. Shared Content Library
E. Subscribed Content Library
【多选题】
An administrator cannot enable multi-processor Fault Tolerance (SMP-FT) for a virtual machine. Which are two possible causes for this? (Choose two.)___
A. The virtual machine is running on a vSAN datastore.
B. The Fault Tolerance network is using a 10Gbit uplink.
C. The virtual machine has 6 vCPUs assigned.
D. The virtual machine has a 1TB VMDK attached.
E. The virtual machine has snapshots present.
【多选题】
Which two statements are true for Predictive DRS? (Choose two.)___
A. It balances resource utilization for virtual machines with unpredictable utilization patterns.
B. It integrates DRS with vRealize Operations Manager to balance workloads for virtual machines before resource utilization spikes occur.
C. It balances resource utilization based on a threshold's algorithm that runs each night.
D. It determines the best placement and balance of virtual machines based on a threshold's algorithm that runs each night in vCenter Server 6.5 Database.
【多选题】
Which two situations could cause a virtual machine to appear with (orphaned) appended to its name? (Choose two.)___
A. if a host failover is unsuccessful
B. if a virtual machine was removed from vCenter Server's inventory
C. if a virtual machine was deployed from template, and the template has been deleted
D. if a virtual machine is unregistered directly on the host
【多选题】
Which three requirements are needed to apply RAID 5 or RAID 6 erasure coding on a vSAN 6.2 or 6.5 object? (Choose three.)___
A. on Disk Format 3.0
B. Hybrid vSAN
C. All Flash vSAN
D. vSAN Advanced License
E. Stretched Cluster Configurations
【多选题】
An administrator sees the following error in the log files: Which two events could be the source of the error message? (Choose two.)___
A. vCenter Server failure
B. VXLAN failure
C. Disk array failure
D. Network failure
E. ESXi host failure
【多选题】
An administrator is attempting to access an ESXi host via the DCUI but is unable to do so. Which could be two possible causes? (Choose two.)___
A. The host in Qhas no out-of-band management capability (i.e. iLO/iDRAC).
B. The SSH service is disabled on the host.
C. Strict lockdown mode is enabled on the host.
D. Normal lockdown mode is enabled and the administrator is a member of the
E. xception User list.
【多选题】
Which two permissions are required to migrate a virtual machine with Storage vMotion? (Choose two.)___
A. Network > Move Network
B. Virtual Machine > Inventory > Move
C. Resource > Migrate powered on virtual machine
D. Datastore > Allocate Space
【多选题】
Which are three supported storage requirements for vCenter Server HA? (Choose three.)___
A. NFS
B. RDM
C. vSAN
D. VMFS
E. JBOD
【多选题】
Which are the two network requirements for a VMware vSAN 6.5 cluster? (Choose two.)___
A. Multicast must be enabled on the physical switches and routers that handle vSAN traffic.
B. vSAN requires IPv6 only.
C. All hosts must have a dedicated 40GbE NIC.
D. The vSAN network supported IPv4 or IPv6.
E. vSAN requires IPv4 only.
【多选题】
Which three prerequisites must be in place prior to enabling secure boot for a virtual machine? (Choose three.)___
A. VirtualMachine.Config.Settings privileges
B. an encrypted USB drive
C. Virtual Hardware version 13 or later
D. Virtual Hardware version 12 or later
E. EFI firmware
【多选题】
A user is given the "Virtual machine user (sample)" role in a vSphere 6.x environment. Which three permissions would the user be able to perform? (Choose three.)___
A. Reset a virtual machine.
B. Power on a virtual machine.
C. Move a host into a cluster.
D. Configure CD media.
E. Migrate a virtual machine with Storage vMotion.
【多选题】
Which three are supported upgrade processes for ESXi host? (Choose three.)___
A. using vSphere Auto Deploy
B. using a TFTP server
C. using Update Manager
D. using an
E. SXCLI command
【多选题】
When enabling Storage DRS on a datastore cluster, which three components are enabled as a result? (Choose three.)___
A. Space load balancing among datastore within the datastore cluster.
B. Initial placement for virtual disks based on space and I/O workload.
C. I/O load balancing among datastores within the datastore cluster.
D. Queue Depth alerting on disks within the datastore cluster.
E. Data de-duplication within the datastore cluster.
【多选题】
What are two features introduced in Network I/O Control version 3? (Choose two.)___
A. Bandwidth reservation per traffic type
B. Network resource pools
C. CoS tagging
D. Bandwidth guarantee to virtual machines
【多选题】
Which two correct virtual machine advanced configuration parameters will accomplish this? (Choose two.)___
A. isolation.device.edit.disable = “FALSE”
B. isolation.device.edit.disable = “TRUE”
C. isolation.device.connectable.disable = “FALSE”
D. isolation.device.connectable.disable = “TRUE”
【多选题】
Which three statements are correct regarding booting an ESXi Host from Fibre Channel SAN? (Choose three.)___
A. Direct connect topology is supported.
B. Each host must have its own boot LUN.
C. ESXi hosts do not require local storage.
D. Multipathing to a boot LUN on an active-passive array is supported.
E. Hosts can share one common boot LUN.
【多选题】
Which two tasks should a vSphere administrator perform if the vmkernel log reports VMFS metadata errors? (Choose two.)___
A. contact VMware technical support
B. reformat the datastore
C. check the device with VOMA
D. ignore the messages
【多选题】
Which two statements are true for a vCenterServer user account that is used for vSphere Data Protection (VDP)? (Choose two.)___
A. The user account must be assigned with Administrator role.
B. The password for the user account cannot contain spaces.
C. The user account should be created in the Single Sign-On domain
D. The user account cannot inherit required permissions from a group role.
【多选题】
Which three storage protocols are supported by Virtual Volumes? (Choose three.)___
A. FCIP
B. FCoE
C. iSCSI
D. NFS v3
E. NFS v4
【多选题】
A vSphere administrator observes a CPU spike on one of the web servers (view the Exhibit.) Which two statements can describe the cause of this activity? (Choose two.)___
A. The network packet size is too large.
B. VMware Tools is not installed.
C. Disk latency is present on the datastore.
D. The network packet size is too small.
【多选题】
Which three operations can cause VMFS metadata updates? (Choose three.)___
A. Restarting a VM using the guest OS.
B. Launching a VM console.
C. Migrating a VM with vMotion.
D. Powering a VM on or off.
E. Expanding a VMFS datastore.
【多选题】
*What two services run on all nodes in a vCenter Server HA cluster? (Choose two.)___
A. vmware-vmon
B. vmware-vpostgres
C. vmare-rbd-watchdog
D. vmware-vcha
【多选题】
Which two statements are true regarding Auto Deploy in version 6.5? (Choose two.)___
A. Auto Deploy can be configured and managed via PowerCLI.
B. Auto Deploy can be configured and managed via the vSphere Client.
C. Auto
D. eploy can be configured and managed via the vSphere Web Client.
【多选题】
What three options can improve network performance for a virtual machine? (Choose three.)___
A. MLD
B. TSO
C. NetFlow
D. LRO
E. SR-IOV
【多选题】
Which two storage technologies are supported for MSCS? (Choose two.)___
A. NFS
B. VAAI
C. iSCSI
D. FC
【多选题】
When upgrading a VMware vSAN cluster to version 6.5, which two tasks must be completed to comply with upgrade requirements and VMware-recommended best practices? (Choose two.)___
A. Use RVC to upgrade the hosts.
B. Use the latest available ESXi version.
C. Back up all VMs.
D. Use only the “Full data migration” maintenance mode option.
【多选题】
What two enhancements are in VMFS6 but not in VMFS5? (Choose two.)___
A. Support for 4k native disks
B. Support for 512e disks
C. GPT storage device partitioning
D. Automatic space reclamation
【多选题】
Which two statements describe why a vSphere DRS cluster would report load imbalance? (Choose two.)___
A. The configured migration threshold is too high.
B. The configured migration threshold is too low.
C. DRS is configured for Partially Automated.
D. Enhanced vMotion Compatibility (EVC) is enabled.
【多选题】
A vSphere Administrator must ensure that vCenter Server service is running in a domain user account rather than Local System Account. To accomplish this, the user account should have which two permissions? (Choose two.)___
A. Log on as a service.
B. Act as part of the operating system.
C. Log on as a batch job.
D. Log on locally.
【多选题】
A virtual machine fails to power on after being deployed from a template. What two remediation steps could correct this issue? (Choose two.)___
A. Increase CPU reservation
B. Decrease memory reservation
C. Increase memory reservation
D. Increase datastore capacity
E. Decrease CPU reservation
【多选题】
Which three directories are available under the vcsa-cli-installer folder of the vCenter Server Appliance installation media? (Choose three.)___
A. \mac
B. \ovftool
C. \migration-assistant
D. \win32
E. \lin64
【多选题】
What are three considerations when booting ESXihost from SAN software FCoE? (Choose three.)___
A. The VMware_FCoE_vSwitch that the installer automatically created cannot be changed.
B. Boot LUN cannot be shared with other hosts even on shared storage.
C. Multipathing is not supported at pre-boot.
D. Software FCoE boot configuration cannot be changed from within
E. SXi.
【多选题】
Which two choices are applicable to vSphere Availability? (Choose two.)___
A. Heartbeat Datastores
B. VM Startup/Shutdoown
C. Power Management
D. Admission Control