2003本系网络考试V1.0(答案).docVIP

浙江大学玉泉校区计算机学院2002-2003学年第二学期《计算机网络》期末试卷（闭卷） 时间：120分钟????????专业________班级________学号________?姓名________成绩________ ?Please choose true(√) or false(×) for the following questions (20x1 points) X A goal that is starting to become more important is doing business with consumers over the Internet. This sector is expected to grow quickly in the future. It is called m-commerce. X One type of person-to-person communication often goes by the name of end-to-end communication, to distinguish it from the client-server model. X P2P, full name is Person-to-person. V Connection-oriented service is modeled after the telephone system. In contrast, connectionless service is modeled after the postal system. X Shannon’s major result is that the maximum data rate of a noisy channel whose bandwidth is H Hz, and whose signal-to-noise ratio is S/N, is given by Maximum number of baud/sec = H log2 (1+S/N) V ADSL stands for Asymmetric Digital Subscriber Line. X When you or your computer places a telephone call, the switching equipment within the telephone system seeks out a physical path all the way from your telephone to the receiver’s telephone. This technique is called message switching. X Rate-based flow control, the receiver sends back information to the sender giving it permission to send more data or at least telling the sender how the receiver is doing. V Protocols in which the sender waits for positive acknowledgement before advancing to the next data item are often called PAR or ARQ. V Go back N, is for the receiver simply to discard all subsequent frames, sending no acknowledgments for the discarded frames. V CSMA/CD is the abbreviation for Carrier Sense Multiple Access with Collision Detection. X The problem of a station not being able to detect a potential competitor for the medium because the competitor is too far away is called the exposed station problem. The reverse situation is called the hidden station problem. V With Manchester encoding, each bit period is div