📄 模拟考试18.htm
字号:
onfocus="this.className='inputedit';this.select()" type=radio
value=D>D.24<BR></TD></TR>
<TR class=trh1>
<TD align=middle height=212 width=29>29 </TD>
<TD align=left height=212 width=607> 设有某一个令牌环网长度为 400 米，环上有
28 个站点，其数据传输率为 4MbpS，环上信号的传播速度为 200 米/μS，每个站点具有 1bit 时延，则环上可能存在的最大时延是©)
<BR>答： <INPUT class=radio name=text1647
onblur="this.className='radio'"
onfocus="this.className='inputedit';this.select()" type=radio
value=A>A.9<BR> <INPUT class=radio name=text1647
onblur="this.className='radio'"
onfocus="this.className='inputedit';this.select()" type=radio
value=B>B.28<BR> <INPUT class=radio name=text1647
onblur="this.className='radio'"
onfocus="this.className='inputedit';this.select()" type=radio
value=C>C.36<BR> <INPUT class=radio name=text1647
onblur="this.className='radio'"
onfocus="this.className='inputedit';this.select()" type=radio
value=D>D.48<BR></TD></TR>
<TR class=trh1>
<TD align=middle height=212 width=29>30 </TD>
<TD align=left height=212 width=607> 在一个带宽为
3KHZ、没有噪声的信道，传输二进制信号时能够达到的极限数据传输率为__(6)__。©) <BR>答： <INPUT
class=radio name=text1651 onblur="this.className='radio'"
onfocus="this.className='inputedit';this.select()" type=radio
value=A>A.3Kbps<BR> <INPUT class=radio name=text1651
onblur="this.className='radio'"
onfocus="this.className='inputedit';this.select()" type=radio
value=B>B.6Kbps<BR> <INPUT class=radio name=text1651
onblur="this.className='radio'"
onfocus="this.className='inputedit';this.select()" type=radio
value=C>C.56Kbps<BR> <INPUT class=radio name=text1651
onblur="this.className='radio'"
onfocus="this.className='inputedit';this.select()" type=radio
value=D>D.10Mbps<BR></TD></TR>
<TR class=trh1>
<TD align=middle height=212 width=29>31 </TD>
<TD align=left height=212 width=607> 在一个带宽为
3KHZ、没有噪声的信道，一个带宽为 3KHZ、信噪比为 30dB 的信道。上述结果表明，__(8)__。©) <BR>答：
<INPUT class=radio name=text1655 onblur="this.className='radio'"
onfocus="this.className='inputedit';this.select()" type=radio
value=A>A.有噪声信道比无噪声信道具有更大的带宽<BR> <INPUT class=radio
name=text1655 onblur="this.className='radio'"
onfocus="this.className='inputedit';this.select()" type=radio
value=B>B.有噪声信道比无噪声信道可达到更高的极限数据传输率<BR> <INPUT
class=radio name=text1655 onblur="this.className='radio'"
onfocus="this.className='inputedit';this.select()" type=radio
value=C>C.有噪声信道与无噪声信道没有可比性<BR> <INPUT class=radio
name=text1655 onblur="this.className='radio'"
onfocus="this.className='inputedit';this.select()" type=radio
value=D>D.上述值都为极限值，条件不同，不能进行直接的比较<BR></TD></TR>
<TR class=trh1>
<TD align=middle height=212 width=29>32 </TD>
<TD align=left height=212 width=607> 根据奈奎斯特第一定理，为了保证传输质量，为达到
3KbpS 的数据传输车需要的带宽为___(9)___。©) <BR>答： <INPUT class=radio
name=text1657 onblur="this.className='radio'"
onfocus="this.className='inputedit';this.select()" type=radio
value=A>A.3KHz<BR> <INPUT class=radio name=text1657
onblur="this.className='radio'"
onfocus="this.className='inputedit';this.select()" type=radio
value=B>B.6KHz<BR> <INPUT class=radio name=text1657
onblur="this.className='radio'"
onfocus="this.className='inputedit';this.select()" type=radio
value=C>C.2KHz<BR> <INPUT class=radio name=text1657
onblur="this.className='radio'"
onfocus="this.className='inputedit';this.select()" type=radio
value=D>D.56KHz<BR></TD></TR>
<TR class=trh1>
<TD align=middle height=212 width=29>33 </TD>
<TD align=left height=212 width=607>
在一个无限带宽的无噪声信道上，传输二进制信号，当信号的带宽为 3KHz 时，能达到的极限数据传输率为__(10)__Kbps 。©) <BR>答：
<INPUT class=radio name=text1659 onblur="this.className='radio'"
onfocus="this.className='inputedit';this.select()" type=radio
value=A>A.1.5<BR> <INPUT class=radio name=text1659
onblur="this.className='radio'"
onfocus="this.className='inputedit';this.select()" type=radio
value=B>B.3<BR> <INPUT class=radio name=text1659
onblur="this.className='radio'"
onfocus="this.className='inputedit';this.select()" type=radio
value=C>C.6<BR> <INPUT class=radio name=text1659
onblur="this.className='radio'"
onfocus="this.className='inputedit';this.select()" type=radio value=D>D.3
log23<BR></TD></TR>
<TR class=trh1>
<TD align=middle height=212 width=29>34 </TD>
<TD align=left height=212 width=607> 与线路交换相比，最大的缺点是__(12)__©)
<BR>答： <INPUT class=radio name=text1663
onblur="this.className='radio'"
onfocus="this.className='inputedit';this.select()" type=radio
value=A>A.增大延迟<BR> <INPUT class=radio name=text1663
onblur="this.className='radio'"
onfocus="this.className='inputedit';this.select()" type=radio
value=B>B.不能实现链路共享<BR> <INPUT class=radio
name=text1663 onblur="this.className='radio'"
onfocus="this.className='inputedit';this.select()" type=radio
value=C>C.不能实现速率转换<BR> <INPUT class=radio
name=text1663 onblur="this.className='radio'"
onfocus="this.className='inputedit';this.select()" type=radio
value=D>D.不能满足实时应用要求<BR></TD></TR>
<TR class=trh1>
<TD align=middle height=212 width=29>35 </TD>
<TD align=left height=212 width=607> 图一为两个局域网 LAN1 和 LAN2
通过网桥 1 和网桥 2 互连后形成的网络结构。设站 A
发送一个帧，但其目的地址均不在这两个网桥的地址转发表中，这样结果会是该帧__(18)__。©) <BR>
<CENTER><IMG border=0 src="模拟考试18.files/200481394246wso3x8.gif">
</CENTER><BR>答： <INPUT class=radio name=text1675
onblur="this.className='radio'"
onfocus="this.className='inputedit';this.select()" type=radio value=A>A.经桥
1（或桥 2）后被站 B 接收<BR> <INPUT class=radio name=text1675
onblur="this.className='radio'"
onfocus="this.className='inputedit';this.select()" type=radio value=B>B.被桥
1（或桥 2 ）丢弃<BR> <INPUT class=radio name=text1675
onblur="this.className='radio'"
onfocus="this.className='inputedit';this.select()" type=radio
value=C>C.在整个网络中无限次地循环下去<BR> <INPUT class=radio
name=text1675 onblur="this.className='radio'"
onfocus="this.className='inputedit';this.select()" type=radio value=D>D.经桥
1 ( 或桥 2 ）到达 LAN2，再经桥 2 ( 或桥 1 ）返回 LAN1 后被站 A 吸收<BR></TD></TR>
<TR class=trh1>
<TD align=middle height=212 width=29>36 </TD>
<TD align=left height=212 width=607> 在使用路由器 R 的 TCP/IP
网络中，两主机通过一路由器互联，提供机器之间通信的层是__(22)__©) <BR>答： <INPUT class=radio
name=text1688 onblur="this.className='radio'"
onfocus="this.className='inputedit';this.select()" type=radio
value=A>A.应用层<BR> <INPUT class=radio name=text1688
onblur="this.className='radio'"
onfocus="this.className='inputedit';this.select()" type=radio
value=B>B.传输层<BR> <INPUT class=radio name=text1688
onblur="this.className='radio'"
onfocus="this.className='inputedit';this.select()" type=radio value=C>C.
IP层<BR> <INPUT class=radio name=text1688
onblur="this.className='radio'"
onfocus="this.className='inputedit';this.select()" type=radio
value=D>D.网络接口层<BR></TD></TR>
<TR class=trh1>
<TD align=middle height=212 width=29>37 </TD>
<TD align=left height=212 width=607> 对照 ISO/OSI
参考模型各个层中的网络安全服务，在物理层可以采用__(26)__加强通信线路的安全©) <BR>答： <INPUT
class=radio name=text1690 onblur="this.className='radio'"
onfocus="this.className='inputedit';this.select()" type=radio
value=A>A.防窃听技<BR> <INPUT class=radio name=text1690
onblur="this.className='radio'"
onfocus="this.className='inputedit';this.select()" type=radio
value=B>B.防火墙技术<BR> <INPUT class=radio name=text1690
onblur="this.className='radio'"
onfocus="this.className='inputedit';this.select()" type=radio
value=C>C.防病毒技术<BR> <INPUT class=radio name=text1690
onblur="this.className='radio'"
onfocus="this.className='inputedit';this.select()" type=radio
value=D>D.防拒认技术 <BR></TD></TR>
<TR class=trh1>
<TD align=middle height=212 width=29>38 </TD>
<TD align=left height=212 width=607> 对照 ISO/OSI
参考模型各个层中的网络安全服务，在数据链路层，可以采用__(27)__进行链路加密©) <BR>答： <INPUT
class=radio name=text1694 onblur="this.className='radio'"
onfocus="this.className='inputedit';this.select()" type=radio
value=A>A.公钥基础<BR> <INPUT class=radio name=text1694
onblur="this.className='radio'"
onfocus="this.className='inputedit';this.select()" type=radio
value=B>B.Kerberos 鉴别<BR> <INPUT class=radio
name=text1694 onblur="this.className='radio'"
onfocus="this.className='inputedit';this.select()" type=radio
value=C>C.通信保密机 <BR> <INPUT class=radio name=text1694
onblur="this.className='radio'"
onfocus="this.className='inputedit';this.select()" type=radio value=D>D.CA
认证中心<BR></TD></TR>
<TR class=trh1>
<TD align=middle height=212 width=29>39 </TD>
<TD align=left height=212 width=607> 对照 ISO/OSI
参考模型各个层中的网络安全服务，在传输层主要解决进程到进程间的加密，最常见的传输层安全技术有__(29)__©) <BR>答：
<INPUT class=radio name=text1699 onblur="this.className='radio'"
onfocus="this.className='inputedit';this.select()" type=radio
value=A>A.SET<BR> <INPUT class=radio name=text1699
onblur="this.className='radio'"
onfocus="this.className='inputedit';this.select()" type=radio
value=B>B.IPsec<BR> <INPUT class=radio name=text1699
onblur="this.className='radio'"
onfocus="this.className='inputedit';this.select()" type=radio
value=C>C.S-HTTP<BR> <INPUT class=radio name=text1699
onblur="this.className='radio'"
onfocus="this.className='inputedit';this.select()" type=radio
value=D>D.SSL <BR></TD></TR>
<TR class=trh1>
<TD align=middle height=212 width=29>40 </TD>
<TD align=left height=212 width=607> 对照 ISO/OSI
参考模型各个层中的网络安全服务，为了将低层安全服务进行抽象和屏蔽，最有效的一类做法是可以在传输层和应用层之间建立中间件层次实现通用的安全服务功能，通过定义统一的安全服务接口向应用层提供__(30)__安全服务。©)
<BR>答： <INPUT class=radio name=text1701
onblur="this.className='radio'"
onfocus="this.className='inputedit';this.select()" type=radio
value=A>A.身份认证<BR> <INPUT class=radio name=text1701
onblur="this.className='radio'"
onfocus="this.className='inputedit';this.select()" type=radio
value=B>B.访问控制 <BR> <INPUT class=radio name=text1701
onblur="this.className='radio'"
onfocus="this.className='inputedit';this.select()" type=radio
value=C>C.身份认证、访问控制和数据加密<BR> <INPUT class=radio
name=text1701 onblur="this.className='radio'"
onfocus="this.className='inputedit';this.select()" type=radio
value=D>D.数据加密<BR></TD></TR>
<TR class=trh1>
<TD align=middle height=212 width=29>41 </TD>
<TD align=left height=212 width=607> TCP
是一个面向连接的协议，它提供连接的功能是__(31)__的©) <BR>答： <INPUT class=radio
name=text1703 onblur="this.className='radio'"
onfocus="this.className='inputedit';this.select()" type=radio value=A>A.
全双工<BR> <INPUT class=radio name=text1703
onblur="this.className='radio'"
onfocus="this.className='inputedit';this.select()" type=radio
value=B>B.半双工<BR> <INPUT class=radio name=text1703
onblur="this.className='radio'"
onfocus="this.className='inputedit';this.select()" type=radio
value=C>C.单工<BR> <INPUT class=radio name=text1703
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