In the following essay, each blank has four choices. Choose the most suitable one from the four choices and write down in the answer sheet.Open Shortest Path First (OSPF) is a (1) routing algorithm that (2) work done on the OSI IS-IS intradomain routing protocol. This routing, as compared to distance-vector routing, requires (3) processing power. The (4) algorithm is used to calculate routes. OSPF routing table updates only take place when necessary, (5) at regular intervals. 1()
A. distance-vector
B. link-state
C. flow-based
D. selective flooding
查看答案
Packet-switching wireless networks are preferable (41) when transmissions are (42) because of the way charges are (43) per packet. Circuit-switched networks are preferable for transferring large files or for other lengthy transmissions because customers are (44) for the (45) of time they use the net-work.
A. to
B. for
C. than
D. only
为了进行差错控制,必须对传送的数据帧进行校验。在局域网中广泛使用的校验方法是 (1) 校验。CRC-16标准规定的生成多项式为G(x)=X16+X15+X2+1,它产生的校验码是 (2) 位,接收端发现错误后采取的措施是 (3) 。如果CRC的生成多项式为G(X)=X4+X+1,信息码宇为10110,则计算出的CRC校验码是 (4) 。要检查出d位错,码字之间的海明距离最小值应为 (5) 。 5()
A. d
B. d+1
C. d-1
D. 2d+1
帧中继网的虚电路建立在 (1) ,在用户层面采用的协议是 (2) 。这种网络没有流量控制功能,但增加了拥塞控制功能。如果沿着帧传送方向出现了拥塞,则把帧地址字段中的 (3) 位设置为1,这样接收方就可通过 (4) 协议要求发送方降低数据速率。最适合提供帧中继业务的网络是 (5) 。 1()
A. 数据链路层
B. 网络层
C. 传输层
D. 会话层
配置WWW服务器是UNIX操作平台的重要工作之一,而Apach是目前应用最为广泛的Web服务器产品之一, (1) 是Apache的主要配置文件。URL根目录与服务器本地目录之间的映射关系是通过指令 (2) 设定;指令Server- Admin的作用是 (3) :而设置index.html或default.html为目录下默认文档的指令是 (4) ;如果允许以"http://www.xxx.edu.cn/~username"方式访问用户的个人主页,必须通过 (5) 指令设置个人主页文档所在的目录。 1()
A. httpd.conf
B. srm.conf
C. access.conf
D. apache.conf