Computer Communication simulation Question 1 (from "100,000 why" Computer Learning Network http://www.why100000.com)

1. Fill in blank questions (1 point for each blank question, 30 points in total)
1. Based on the signal transmission direction on the channel, data communication methods can be divided into <>>, <>, and <> 〈〉,〈〉,〈〉.
2. Five management functions are defined in the OSI Management System: <>>, <>, and <> 〈〉,〈〉,〈〉,〈〉,〈〉.
3. connection-oriented services have three stages: <>, <>, and <>.
4. Data communication refers to <> 〈〉.
5. The functions of computer networks are as follows 〈〉,〈〉,〈〉,〈〉.
6. The TCP/IP system has four levels: <>, and <> 〈〉.
7. The meaning of ISDN is <> 〈〉.
8. bandwidth refers to <> in analog communication and <> in digital communication 〈〉.
9. Novell's NetWare operating system adopts NLM technology. NLM refers to <> 〈〉.
10. There are different definitions of computer networks in different periods. Currently, the definition of computer networks is more consistent 〈〉.
11. The main task of the physical layer is to determine the characteristics related to the transmission media, that is, the <> features, <> features, <> features and <> features.
12. SNMP in the internet refers to <> and PPP refers to <> 〈〉.

2. multiple choice questions (1 point for each question, 20 points in total)
1. Which of the following does not belong to the network topology 〈〉.
A. Star structure B. Bus Structure C. Hierarchical Structure D. Mesh Structure
2. Compared with the circuit switching mode, the group switching mode has the advantage of <> 〈〉.
A. Accelerated transmission speed B. Improved the effective utilization of the line
C. Simple control, high reliability, good real-time performance
3. Internet is currently the world's largest Internet connection. Its prototype is <> 〈〉.
A, ncfc B, CERNET C, gbnet D, ARPANET
4. The two computers use telephone lines to transmit data signals. The necessary equipment is <> 〈〉.
A. Nic B, repeater C, modem D, coaxial cable
5. Both slip and PPP protocols are <> protocols.
A. Physical Layer B. data link layer C. Network Layer D. Transport Layer
6. When the signal is sent, the encoding is not required 〈〉.
A. analog data analog signal sending B. analog data digital signal sending
C. Digital Data Digital Signal Transmission D. Digital Data Analog Signal Transmission
7. The cable can be described at the same time as the maximum data transmission speed it can process. The data transmission speed is expressed by the bytes transmitted per second. For example, 100base is a very common type, indicating that the cable is in the baseband type and can be transmitted at a rate of <> second.
A, 10 B, 20 C, 50 d, 100
8. A repeater is a device used in <> to extend the length of a physical line.
A. Physical Layer B. data link layer C. Network Layer D. Transmission Layer
9. Which of the following statements about the Ethernet NIC address is true 〈〉.
A. Globally Unique B. globally unique
C. Unique within a certain range D. Not unique within a certain range
10. Which of the following statements about the OSI reference model is true 〈〉.
A. direct communication between each layer B. direct data transmission at the physical layer
C. Data is always transmitted from the application layer to the physical layer D. Data is always transmitted from the physical layer to the Application Layer
11. In the TCP/IP protocol set, the <> Protocol is required for each application.
A. TCP (Transmission Control Protocol) B. IP (Internet Protocol)
C. UDP (User Datagram Protocol) D. ARP (Address parsing Protocol)
12. When the receiving end detects an error, try to notify the sending end to resend until the correct code word is received. This error control method is called <> 〈〉.
A. Forward correction B. Automatic request resend C. Hybrid Error Control D. redundancy check
13. The physical layer uses the <> method to achieve physical connections.
A. Four features stipulated by physical device B, physical media C, transmission error control d, and physical layer protocol
14. SNA is the network system launched by <>.
A, Dec B, IBM C, CCITT D, IEEE
15. In PCM modulation, the standard rate of T1 link is <> 〈〉.
A. 1.544 m B, 3.096 M C, 2.048 M D, 8000 K
16. The synchronization protocol in the data link layer protocol is primarily a unit of transmission information.
A. Packet B, frame C, character D, bit
17. In an ATM network, the ATM node <> 〈〉.
A. Only perform CRC check on the header without error control.
B. Do not check the CRC of the header, and do not control errors
C. Both CRC check of the header and Error Control
D. Do not check the CRC of the header and only control errors.
18. Windows NT4.0 adopts the <> technology to implement a cross-multi-CPU platform.
A, dll B, NLM C, Hal D, NDIS
19. Among the three types of network services, X.25 is <> 〈〉.
A, type a B, type B C, type C D, uncertain
20. In the TCP/IP application, <> is used to test whether hosts on the network are accessible.
A, ftp B, TFTP C, Ping D, rexec

Iii. Calculation questions (10 points for each question, a total of 20 points)
1. What is the maximum data rate for a channel with a bandwidth of 64 KB, which of the following four levels can be obtained for a digital signal at any time?
2. If the generated polynomial is 10111 and the information bit is 11111011, obtain the code word generated after the cyclic percentile bit and added to the information bit. If the code is sent by HDLC (bit filling), obtain the sending sequence.

4. Application Questions (6 points per question, 30 points in total)
1. Analyze the three concession algorithms commonly used by CSMA technology;
2. Analyze the hub limitations in the LAN;
3. What is ATM? Which connection methods are available? What are their characteristics?
4. What is the purpose of the subnet mask?
5. determine which of the following IP addresses are invalid and describe the reasons for their invalidity.
131.0000000018
127.21.19.109
220.103.256.56
240.9.12.12
192.5.91.255
129.9.255.254
10.20.255.254
-----------------------------------------------------------------
Blog: Zhang Qing zhangking@263.net
QQ: 9365822
MSN: zhangking@hotmail.com
Personal Homepage: http://www.why100000.com ("100,000 why" computer learning network)
Other Websites: http://sogo99.com (sogou 99 web portal)
Http://neteye.blogchina.com
2004.11.5