试解释everything over IP 和IP over everthing 的含义？

A . 网络体系结构复杂 B . 传输效率低 C . 不适应于多业务 D . 网络体系结构复杂和传输效率低

A . SDH帧格式 B . GE以太网帧格式 C . PDH帧格式 D . SDH帧格式或GE以太网帧格式

A . A voice packet is sent via multiple fixed-length cells; a portion of the last cell is padding, requiring more bandwidth. B . ADSL typically uses PPPoE encapsulation, which adds additional overhead to each voice packet. C . A voice packet is sent via multiple fixed-length cells; each cell has about 10% Layer-2 header overhead.  D . IPSec requires additional overhead for the header and hash.  E . ADSL carrier band requires additional bits to be carried over the wire to the DSL Access Concentrator.

A . IP Over SDH通常应用于点到点链路中 B . IP Over ATM提供丰富的QoS功能 C . IP Over ATM设备成本较高 D . 目前IP Over SDH更适宜普及

A . 79xx IP phones do not automatically mark voice packets with non-zero DSCP values. B . 79xx IP phones do not mark protocol packets such as DHCP, DNS, or TFTP with non-zero DSCP values. C . 79xx IP phones do not mark voice packets with optimal DSCP values. D . 79xx IP phones use a custom protocol to communicate CDP information to the switch.

A . 正确 B . 错误

A .  Packets can arrive out of order. B .  Packets must take the same path to the destination. C .  Once packets are received at the destination router， the router performs sampling to ensure the quality of the voice traffic. D .  Packets can experience varying delays across the network. E .  Packets containing voice samples are sequentially numbered by default， allowing for reordering upon arrival at the terminal router along the path.

A . 正确 B . 错误

A . WDM B . OA C . OTU D . POS

A .  Some network attributes are runtime attributes that can be changed at any time. Others are loadtime attributes that must be set before the netinet kernel extension is loaded and be placed in the /etc/rc.net or /etc/rc.bsdnet file. This parameter cannot be done on the fly， since a reboot is required. B .  Add to the /etc/rc.net file or if a Berkelye-style network configuration， /etc/rc.bsdnet， and issue the command： no -a ipforwarding=1 to start ipforwarding immediately. C .  Add to the /etc/rc.net file or if a Berkeley-style network configuration， /etc/rc.bsdnet， and issue the command： no -o ipforwarding=0 to start ipforwarding immediately. D .  Add to the /etc/rc.net file or if a Berkeley-style network configuration， /etc/rc.bsdnet， and issue the command： no -o ipforwarding=1 to start ipforwarding immediately.

A . 正确 B . 错误

Network managers have long awaited practical voice-over-IP(VOIP)solutions. VOIP promises(71)network management and decreases costs by(72)a company's telephony and data infrastructures into one network. And a VOIP solution implemented at a company' s head -quarters with far -reaching branch offices can(73)tremendous amounts of(74)in long distance phone bills, provided that solution delivers POTS -like voice(75)over the Internet. A．complicated B．useful C．ease D．orderly

<span style="line-height:0px;"><span style="line-height:0px;">‍</span></span><span style="line-height:0px;">‍</span>试解释“TCP/IP协议”<span style="line-height:0px;">‍</span><span style="font-family:simsun;font-size:14px;line-height:24px;background-color:rgb(255,255,255);"><span style="line-height:0px;">‍</span></span>

A．按正常工作位置放置 B．按最大接受粉尘位置放置 C．设备在正常情况下开启的泄水孔在试验期间保持开启 D．设备在正常情况下开启的泄水孔在试验期间保持关闭

A．A.PPP和HDLC B．B.PPP和SDH C．C.HDLC和SDH D．D.IP和PPP