1. Which of the following does not belong to the end system?D
A, the PC
B. Server
C. Notebook
D. Router
2. Which of the following is the guided transmission media?A.
A. Twisted pair
B, WiFi,
C. Satellite communications
D. Microwave communication
3. Which of the following is the advantage of wireless communication?D
A, the reflection
B. Building barriers
C, interference
D, convenient
4. Which of the following is the main method of home access?(A)
A. ADSL (Family)
B. Local area network (organization-level network)
C. HDDI(Man)
5. Packet switching allows more users to use the network?T
6. Circuit switched networks are more prone to packet loss and delay?F
7. The formula of propagation delay is D /s T
8. The correct description of flow intensity is (A)
A. When the flow intensity approaches 0, the queuing delay is very small
B. When the flow intensity approaches 0, the queuing delay is very large
C. When the flow intensity approaches 1, the queuing delay is very small
D. When the flow intensity approaches 1, the link is in an idle state
9.Traceroute is the command that measures which routers pass through a timely delay from the source to the destination T
10. What is the throughput in the figure below?(A)
A, the Rs
B, Rc
C, (Rs+Rc) / 2
11.End system are connected together by (A).
A. the communication links
B. the application layer
C. the transport layer
D. the network layer
The () is a worldwide computer network, that is, a network that interconnects millions of computing devices throughout The world.(B)
A. the public Internet
B. Intranet
C. the switch net
D. television net
13 Which kind of media is not a guided media?(D)
A. the twisted - pair copper wire
B. a coaxial cable
C. fiber called
D. digital satellite channel
14. Network layering facilitates maintenance and modification of the system?T
15. What is layer 4 of the Internet protocol stack?(B)
A. Network layer
B. Transport layer
C. Link layer
D. Application layer
16. Which of the following functions belongs to the presentation layer of the OSI model?(D)
A. Session synchronization point
B. Route planning
C. Continuation of transmission after breakpoint
D. Data encryption
17. What is the name of the TRANSPORT Layer Protocol data unit?(C)
A, A message
B, frame
C. Message segment
D. Datagram
18. The Internet was not designed with security in mind.T
19. Sniffer can detect sensitive information in packet plaintext T
20. The application can run in the network core F
21. In client-server structure, there is no need for direct communication between clients T
22. In a P2P structure, each peer entity ACTS as both a client and a server.T
23. Identifying a process requires an IP address and host name F
24. The process can send and receive information through the socket T
25.TCP transport has security F
26. The Email application USES UDP protocol at the transport layer F
27. Every object in a web page is addressed by A URL.T
28. The HTTP protocol USES the Client/Server mode T
29. A web page contains 10 picture files, non-persistent connection, how long does it take to receive all objects (D)
A. 10RTT+10 object transfer time
B. 11RTT+11 object transfer time
C. 20RTT+10 object transfer time
D. 22RTT+11 object transfer time
30. Cookies exist in the background database of the website (note: cookies are found in the client, background database and HTTP request packets) T
31. Cookies can be used for authentication T
32.Web Cache can reduce link traffic, but not access time F
33. The Web Cache server is generally located within the area network T
34. Using Web Cache, there is no guarantee that the client will get the latest version.F
35.FTP control port is 21, transport layer using UDP protocol F (note: TCP protocol is used)
36. SMTP protocol is used to send messages between mail servers T
37. Which of the following is true about SMTP?(B)
A. UDP is used for the transport layer and the port is 25
B. The transport layer USES TCP and the port is 25
C. The transport layer USES TCP and the port is 110
D. UDP is used for the transport layer and the port is 110
38.DNS USES a distributed and hierarchical structure T
39.DNS converts hostname to IP address T
40. In a DNS query, if the local DNS cache has a name-to-Address mapping pair, it will be returned directly to the client of the query without further accessing T
41. Which of the following is a P2P structure?(D)
A. Use A browser to visit www.tjut.edu.cn
B. FTP client accesses FTP server
C. Use mobile APP to access email
D. Use Thunderbolt to download files
42. Using P2P mode to distribute files, the server does not need to upload a complete file F
43. For N clients, use P2P mode to distribute Faster T
44.P2P distribution. A client can only distribute to other clients if it receives the complete file F
45.BitTorrent divided file into 256Kb chunks T
46.Tracker records the peers information participating in torrent T
The policy for peer entities to acquire file blocks is rare T
48. The peer only sends chunks to those four peers currently sending its ehrs chunks at highest rate, and then randomly select another peer to send within 30 seconds of T
49. In DHT, the key-value pair is stored on its immediate successor, T
50. Each packet sent by UDP does not need to fill in the receiver's IP and Port F
Demultiplexing Occurs at the sender F
52.UDP is the best service T
53 Which of the following USES UDP services at the transport layer?(C)
A, E-mail.
B, FTP
C, SNMP
D, Web
54. What is the checksum of hex C555 and D555?(D)
A, 4443,
B, 5443,
C, 5554
D, 6554
The calculation process is as follows:
1100 0101 0101 0101
+ 1101 0101 0101 0101 0101
= 11001 1010 1010 1010
Plus 1, 1001, 1010, 1010, 1010
So let's take 0110, 0101, 0101, 0100
6, 5, 5, 4
55. In RDT1.0, channels were considered error-free and packet free.T
56. In RDT2.0, the receiver tells the sender whether to receive correctly through ACK and NAK.T
57. In RDT2.1, determine if the ACK/NAK packet is faulty.T
58. RDT3.0 is functionally flawed.F
59. For backward N, ack (N) means that N and previous packets of N have received T correctly
60 For fallback N, the sender sets a timer F for each sent packet
61. For retransmission, ack(n) indicates that the n packet has received F correctly
62. If the serial number is 4 bits in selected retransmission, the size of the sending window cannot exceed.B is 2 to the fourth divided by 2
4 A,
B, 8
C, 12
D, 16
63. In TCP, ack(n) represents the previous correct receive of N, and you want to get N.T
There is a receive window in the TCP segment. This field is used for ().(B)
A. Congestion control
B. Flow control
C. Fairness
D. Number of bytes to notify the receiver to fetch quickly
65. TCP timeout interval can be set to the size of the previous sample RTT.T
66. With TCP, the current packet number is 100 and the packet length is 20. What is the next packet number?(D)
A, 101,
B, 110,
C, 119
D, 120
67. For TCP receivers, when a packet arrives in sequence and the packet's previous packets have replied ACK, the receiver immediately replies with an ACK F for that packet
68.TCP sender receives three duplicate Acks and immediately retransmits T quickly
69. In a TCP connection, the FIN location of the initiating party is 1 F
70. In TCP traffic, it is assumed that the cache in the router is infinite and no retransmission will cause no congestion.F
71. In TCP congestion control, the network sends a congestion signal to the transmitter F
72. In the figure below, the threshold value of stage 24 (abscissa 24) is (C)
A, 32
B, 21
13 C,
D, 8
73. The datagram enters through the router's entrance, and the output from the corresponding exit is route F
74. The Internet can guarantee the orderly transmission of packets.F
75. The network layer of the same network can provide both connection-oriented services and connection-oriented services F
76. The network layer provides host-to-host service T
77. ATM technologies used in the Internet.F
78. The Internet is characterized by a simple network inside and a complex network edge.T
79. The bus - based architecture of the router has advantages over the memory - based architecture.T
80. The output port of the router does not queue.F
81. The address length of IPv4 is 32 bits.T
82. What kind of address does 202.113.64.9 belong to?(C)
A, A class
B, class B
C, C
D, D class
83. Which of the following belongs to the LAN address?(B)
(note: 10. X.X.X along - 172.31.255.255 192.168 7.0.x.x are LAN address)
A, 15.3.4.6
B, 10.0.0.1
C, 193.4.6.9
D, 174.6.9.2
84.Which of the following subnet masks is incorrect.(C)
A, 255.255.255.0
B, 255.255.0.0
C, 255.255.0.1
D, 255.255.252.0
85.DHCP is suitable for mobile office environment T
86.NAT enables multiple machines on a LAN to access the Internet from a common IP address.T
87.NAT allows internal machines to access external servers, but does not allow external machines to access internal Server F
88.The Ping command USES the ICMP protocol.T
89. The Traceroute command calculates the round-trip delay through the router.T
90.The IPv6 address length is 128bit T
91. The IPv4 upgrade to IPv6 has a anniversary.F
92.The link-state algorithm is a global routing algorithm.T
93. The distance vector algorithm is a static distributed algorithm F
94. C (x,y) refers to the shortest distance between node X and node Y.F
95. The distance vector algorithm only exchanges information with neighboring nodes, so it needs to pass several iterations to converge.T
96. In the distance vector algorithm, good news travels slowly while bad news travels fast.F
The Internet management network is tiled.F
98. The routing algorithm used by the autonomous system is determined by the administrator of the autonomous system.F
99.RIP belongs to the distance vector algorithm, and the notification is transmitted using UDP protocol.T
100. OSPF algorithm belongs to the link-state algorithm, which USES IP datagrams for messaging.T
101. OSPF supports hierarchical routing T
102.BGP routing is a routing protocol between autonomous systems, with policy first and efficiency second.T
103. The link layer protocol data unit is called frame and encapsulates the transport layer segment F
104. Parity checks for 2-digit errors.F
105. In CRC, the generated formula G is 4 bits, then the length of the redundant code R is (B) bits.
A, 2
B, 3
C, 4
D, and 5
106. Which of the following is a point-to-point access method?(A)
A. PPP dial-up access
B. Old-fashioned Ethernet
C, HFC
D, WiFi
107.TDMA belongs to channel division mode.T
108. ALOHA's efficiency is 18%.T(up to 37%)
109. Non-time slot ALOHA requires time synchronization F of all nodes
110.Non-time slot ALOHA, send data as soon as it arrives from the upper level.T
111.CSMA listens to the channel before sending, so there is no conflict.F
112.CSMA/CD will stop sending when there is a conflict, so it will save time?T
113.CSMA/CD, as the number of collisions increases, the delay in sending is bound to be longer.F
114. Polling combines the advantages of channel partitioning, which is more efficient under high loads, and random access, which is more efficient under light loads
115.The MAC address length is (48) bits.T
116.The ARP protocol maps IP addresses to MAC addresses.T