1. The term "Jitter" refers to
A. errorless delivery.
B. variation in the packet arrival time.
C. timely delivery of message.
D. none of the mentioned.
Answer= variation in the packet arrival time
2. 2 Half duplex systems can make a Full-Duplex..
A. TRUE.
B. FALSE.
C. Nothing can be said.
D. None of the mentioned.
Answer= TRUE
3. Which topology requires the most amount of wiring?.
A. Mesh.
B. Star.
C. Bus.
D. Ring.
Answer= Mesh
4. How many links are there for N nodes in the mesh topology?.
A. 1.
B. N(N+1)/2.
C. N.
D. N(N-1)/2.
Answer= N(N-1)/2
5. Which topology has a central hub?.
A. Mesh.
B. Star.
C. Bus.
D. Ring.
Answer= Star
6. Which topology has the toughest fault identification?.
A. Mesh.
B. Star.
C. Bus.
D. Ring.
Answer= Bus
7. Ethernet LANs use which topology?.
A. Mesh.
B. Star.
C. Bus.
D. Ring.
Answer= Bus
8. Which topology uses the token passing algorithm?.
A. Mesh.
B. Star.
C. Bus.
D. Ring.
Answer= Ring
9. How many lines are required for the bus topology?.
A. N(N-1)/2.
B. N.
C. N+1.
D. none of the mentioned.
Answer= N+1
10. A list of protocols used is known as
A. protocol access.
B. protocol stack.
C. permutation stack.
D. none of the mentioned.
Answer= protocol stack
11. In order to prevent a fast sender from swamping a slow receiver with data, feedback is often used. This process is known as
A. flow control.
B. multiplexing.
C. congestion.
D. none of the mentioned.
Answer= flow control
12. If a periodic signal is decomposed into five sine waves with frencies of 100, 300, 500, 700, and 900 Hz, what is its bandwidth?.
A. 2500 Hz.
B. 900 Hz.
C. 800 Hz.
D. can't be determined with the information given.
Answer= 800 Hz
13. Assume we need to download text documents at the rate of 100 pages per second. What is the required bit rate of the channel?.
A. 1.846 Mbps.
B. 1.536 Mbps.
C. 2.4 Mbps.
D. None of the Mentioned.
Answer= 1.536 Mbps
14. A digitized voice channel is made by digitizing a 4-kHz bandwidth analog voice signal. We need to sample the signal at twice the highest frency (two samples per hertz). We assume that each sample requires 8 bits. What is the required bit rate?.
A. 64 kbps.
B. 32 kbps.
C. 128 kbps.
D. 16 kbps.
Answer= 64 kbps
15. What is the bit rate for high-definition TV (HDTV)?.
A. 1.4 Gbps.
B. 2 Gbps.
C. 1.5 Gbps.
D. 1.8 Gbps.
Answer= 1.5 Gbps
16. A device is sending out data at the rate of 1000 bps. How long does it take to send a file of 100,000 characters?.
A. 200s.
B. 400s.
C. 600s.
D. 800s.
Answer= 800s
17. A file contains 2 million bytes. How long does it take to download this file using a 56-Kbps channel?.
A. 1-2 mins.
B. 5-6 mins.
C. 2-4 mins.
D. 7-8 mins.
Answer= 5-6 mins
18. We need to send 265 kbps over a noiseless channel with a bandwidth of 20 kHz. How many signal levels do we need?.
A. 1024.
B. 512.
C. 256.
D. 128.
Answer= 128
19. Calculate the theoretical highest bit rate of a regular telephone line. The signal-to-noise ratio is usually 3162..
A. 34.860 kbps.
B. 17.40 kbps.
C. 11.62 kbps.
D. none of the Mentioned.
Answer= 34.860 kbps
20. Calculate the theoretical channel capacity. If SNR(dB) = 36 and the channel bandwidth is 2 MHz..
A. 12 Mbps.
B. 24 Mbps.
C. 16 Mbps.
D. 32 Mbps.
Answer= 24 Mbps
21. A channel has a 1-MHz bandwidth. The SNR for this channel is 63. What is the appropriate bit rate?.
A. 4 Mbps.
B. 6 Mbps.
C. 8 Mbps.
D. 12 Mbps.
Answer= 6 Mbps
22. A channel has a 1-MHz bandwidth. The SNR for this channel is 63. What is the appropriate signel level?.
A. 2.
B. 8.
C. 4.
D. 16.
Answer= 4
23. What are the bits transmitted for the Unipolar system?.
A. 1101.
B. 11010.
C. 10110.
D. 1001.
Answer= 10110
24. What are the bits transmitted for the NRZ-L system?.
A. 10001101.
B. 1001110.
C. 10110001.
D. 10001101.
Answer= 10110001
25. What are the bits transmitted for the return to zero system?.
A. 1001.
B. 10110.
C. 10010.
D. 1101.
Answer= 1001
26. What are the bits transmitted in the differential Manchester coding?.
A. 1101.
B. 101100.
C. 110010.
D. 10011.
Answer= 10011
27. What are the bits transmitted for the AMI and Pseudoternary System?.
A. 101101.
B. 101100.
C. 10010.
D. none of the mentioned.
Answer= 10010
28. Five channels, each with a 100-kHz bandwidth, are to be multiplexed together. What is the minimum bandwidth of the link if there is a need for a guard band of 10 kHz between the channels to prevent interference?.
A. 4600 kHz.
B. 500 kHz.
C. 540 kHz.
D. 580 kHz.
Answer= 540 kHz
29. Find the checksum byte for the fallowing data words: 10110011, 10101011, 01011010, 11010101.
A. 10001101.
B. 1110010.
C. 10110101.
D. 1110010.
Answer= 10001101
30. Generate the CRC codeword for the message x3+1 using the generator polynomial x3+x+1..
A. 1001101.
B. 1001001.
C. 1001110.
D. 1001111.
Answer= 1001110
31. Generate the CRC codeword for the data word 1101011011 using generator 10011. Also write both in the polynomial form..
A. 1.10101E+13.
B. 1.10101E+13.
C. 1.10101E+13.
D. 1.10101E+13.
Answer= 1.10101E+13
32. What is the hamming distance between these 2 codes: 10010010 and 11011001?.
A. 3.
B. 4.
C. 6.
D. 2.
Answer= 4
33. What is the hamming code for the data: 1001101?.
A. 10011100101.
B. 11010000101.
C. 10001100101.
D. 11111001011.
Answer= 10011100101
34. 10010100101 is the code received. Find the error bit..
A. 7.
B. 5.
C. 2.
D. 3.
Answer= 7
35. The channel capacity is 100Mbps, the frame length is 10000 bits and the arrival rate is 5000 frames/sec. Calculate the mean time delay..
A. 400 µsec.
B. 20 msec.
C. 2000 µsec.
D. 200 µsec.
Answer= 200 µsec
36. A pure ALOHA network transmits 200-bit frames on a shared channel of 200 kbps. What is the requirement to make this frame collision-free?.
A. 2msec.
B. 4msec.
C. 2sec.
D. 4sec.
Answer= 2msec
37. A pure ALOHA network transmits 200-bit frames on a shared channel of 200 kbps. What is the throughput if the system (all stations together) produces 1000 frames per second?.
A. 150 frames.
B. 80 frames.
C. 135 frames.
D. 96 frames.
Answer= 135 frames
38. A pure ALOHA network transmits 200-bit frames on a shared channel of 200 kbps. What is the throughput if the system (all stations together) produces 500 frames per second?.
A. 146 frames.
B. 92 frames.
C. 38 frames.
D. 156 frames.
Answer= 92 frames
39. A pure ALOHA network transmits 200-bit frames on a shared channel of 200 kbps. What is the throughput if the system (all stations together) produces 250 frames per second?.
A. 38 frames.
B. 48 frames.
C. 96 frames.
D. 126 frames.
Answer= 38 frames
40. A slotted ALOHA network transmits 200-bit frames using a shared channel with a 200-kbps bandwidth. Find the throughput if the system (all stations together) produces 1000 frames per second..
A. 92 frames.
B. 368 frames.
C. 276 frames.
D. 151 frames.
Answer= 368 frames
41. A slotted ALOHA network transmits 200-bit frames using a shared channel with a 200-kbps bandwidth. Find the throughput if the system (all stations together) produces 500 frames per second..
A. 92 frames.
B. 368 frames.
C. 276 frames.
D. 151 frames.
Answer= 151 frames
42. A network using CSMA/CD has a bandwidth of 10 Mbps. If the maximum propagation time (including the delays in the devices and ignoring the time needed to send a jamming signal, as we see later) is 25.6 ?s, what is the minimum size of the frame?.
A. 128 bytes.
B. 32 bytes.
C. 16 bytes.
D. 64 bytes.
Answer= 64 bytes
43. In collision free protocol channel efficiency is given by
A. d/(d + log2(N)).
B. d*(d + log2(N)).
C. log2(N).
D. (d + log2(N)).
Answer= d/(d + log2(N))
44. After performing bit stuffing on the following stream : 01101111111111111110010, the output is
A. 1.10111E+24.
B. 1.10111E+24.
C. 1.001E+25.
D. 1.10111E+24.
Answer= 1.10111E+24
45. HTTP stands for ________.
A. Hash Text Transfer Protocol.
B. Hyper Text Transfer Protocol.
C. Hash Transfer Text Protocol.
D. none of the mentioned.
Answer= Hyper Text Transfer Protocol
46. SMTP stands for ________.
A. Service Message Transmission Permission.
B. Secure Message Transfer Protocol.
C. Simple Mail Transfer Protocol.
D. Simple Message Transfer Protocol.
Answer= Simple Mail Transfer Protocol
47. UDP stands for ________.
A. User Datagram Protocol.
B. Used Data Protocol.
C. Unified Definition Protocol.
D. Undefined Diagnostic Protocol.
Answer= User Datagram Protocol
48. ICMP stands for ________.
A. Internal Control Message Protocol.
B. Internet Cipher Mail Protocol.
C. Internal Cipher Mail Protocol.
D. Internet Control Message Protocol.
Answer= Internet Control Message Protocol
49. SONET stands for ________.
A. Secure Offline Network.
B. Synchronous Optical Network.
C. Service Offline Network.
D. Secure Optical Netwrok.
Answer= Synchronous Optical Network
50. DSL stands for ________.
A. Data Storage Line.
B. Digital Subscriber Line.
C. Data Service Language.
D. Data Secure Language.
Answer= Digital Subscriber Line
51. Which of the following does not lie in the Application Layer of the TCP/IP Model?.
A. HTTP.
B. SMTP.
C. RTP.
D. UDP.
Answer= UDP
52. Which one of these does not lie in the Link Layer of the TCP/IP Model?.
A. DSL.
B. IP.
C. SONET.
D. 802.11.
Answer= IP
53. Which of these is a connection oriented service?.
A. X.25.
B. Frame Relay.
C. ATM.
D. All of the mentioned.
Answer= All of the mentioned
54. In terms of the size of the network the correct order (ascending) is
A. PAN, MAN, LAN, WAN.
B. LAN, MAN, WAN, PAN.
C. PAN, LAN, MAN, WAN.
D. LAN, PAN, MAN, WAN.
Answer= PAN, LAN, MAN, WAN
55. How many layers are there in the OSI reference model?.
A. 4.
B. 5.
C. 6.
D. 7.
Answer= 7
56. Logical Addressing and Routing are functions of which layer?.
A. Physical Layer.
B. Transport Layer.
C. Data Link Layer.
D. Network Layer.
Answer= Network Layer
57. Flow Control and Error Control are functions of which layer?.
A. Physical Layer.
B. Application Layer.
C. Data Link Layer.
D. Network Layer.
Answer= Data Link Layer
58. Dialog Control and Synchronization are function of which layer?.
A. Presentation Layer.
B. Application Layer.
C. Session Layer.
D. Data Link Layer.
Answer= Session Layer
59. Encryption and Compression are functions of which OSI layer?.
A. Presentation Layer.
B. Application Layer.
C. Session Layer.
D. Data Link Layer.
Answer= Presentation Layer
60. File, Transfer, Access and Management (FTAM) is a function of which layer ?.
A. Presentation Layer.
B. Application Layer.
C. Session Layer.
D. Data Link Layer.
Answer= Application Layer
61. How many layers are present in the TCP/IP Reference model?.
A. 6.
B. 7.
C. 5.
D. 4.
Answer= 4