Computer Networking

Question 1:
In OSI network architecture, the dialogue control and token management are responsibility of
a. session layer
b. network layer
c. transport layer
d. data link layer
e. none of above

Question 2:
In OSI network architecture, the routing is performed by
a. network layer
b. data link layer
c. transport layer
d. session layer
e. none of above

Question 3:
Which of the following performs modulation and demodulation?
a. fiber optics
b. satellite
c. coaxial cable
d. modem
e. none of the above

Question 4:
The process of converting analog signals into digital signals so they can be processed by a receiving computer is referred to as:
a. modulation
b. demodulation
c. synchronizing
d. digitising

Question 5:
How many OSI layers are covered in the X.25 standard?
a. Two
b. Three
c. Seven
d. Six
e. None of above

Question 6:
Layer one of the OSI model is
a. physical layer
b. link layer
c. transport layer
d. network layer
e. none of above

Question 7:
The x.25 standard specifies a
a. technique for start-stop data
b. technique for dial access
c. DTE/DCE interface
d. data bit rate
e. none of above

Question 8:
Which of the following communication modes support two-way traffic but in only one direction at a time?
a. simplex
b. half duplex
c. three-quarters duplex
d. all of the above
e. none of the above

Question 9:
Which of the following might be used by a company to satisfy its growing communications needs?
a. front end processor
b. multiplexer
c. controller
d. concentrator
e. all of the above

Question 10:
What is the number of separate protocol layers at the serial interface gateway specified by the X.25 standard?
a. 4
b. 2
c. 6
d. 3
3. none of the above


Correct Answers:
1. a
2. a
3. d
4. d
5. b
6. a
7. c
8. b
9. e
10. d
Question 1:
The interactive transmission of data within a time sharing system may be best suited to
a. simplex lines
b. half-duplex lines
c. full duplex lines
d. biflex-lines

Question 2:
Which of the following statement is incorrect?
a. The difference between synchronous and asynchronous transmission is the clocking derived from the data in synchronous transmission.
b. Half duplex line is a communication line in which data can move in two directions, but not at the same time.
c. Teleprocessing combines telecommunications and DP techniques in online activities
d. Batch processing is the prefered processing mode for telecommunication operation.

Question 3:
Which of hte following is considered a broad band communication channel?
a. coaxial cable
b. fiber optics cable
c. microwave circuits
d. all of above

Question 4:
Which of the following is not a transmission medium?
a. telephone lines
b. coaxial cables
c. modem
d. microwave systems

Question 5:
Which of the following does not allow multiple uses or devices to share one communication line?
a. doubleplexer
b. multiplexer
c. concentrator
d. controller

Question 6:
Which of the following signal is not standard RS-232-C signal?
a. VDR
b. RTS
c. CTS
d. DSR

Question 7:
Which of the following statement is incorrect?
a. Multiplexers are designed to accept data from several I/O devices and transmit a unified stream of data on one communication line
b. HDLC is a standard synchronous communication protocol.
c. RTS/CTS is the way the DTE indicates that it is ready to transmit data and the way the DCW indicates that it is ready to accept data
d. RTS/CTS is the way the terminal indicates ringing

Question 8:
Which of the following is an advantage to using fiber optics data transmission?
a. resistance to data theft
b. fast data transmission rate
c. low noise level
d. all of above

Question 9:
Which of the following is required to communicate between two computers?
a. communications software
b. protocol
c. communication hardware
d. all of above including access to transmission medium

Question 10:
The transmission signal coding method of TI carrier is called
a. Bipolar
b. NRZ
c. Manchester
d. Binary

1. b
2. d
3. d
4. c
5. a
6. a
7. d
8. d
9. d
10. a

Question 1:

Which data communication method is used to transmit the data over a serial communication link?

a. simplex

b. half-duplex

c. full-duplex

d. b and c

e. None of above

Question 2:

What is the minimum number of wires needed to send data over a serial communication link layer?

a. 1

b. 2

c. 4

d. 6

e. none of above

Question 3:

Which of the following types of channels moves data relatively slowly?

a. wide band channel

b. voice band challen

c. narrow band channel

Question 4:

Most data communications involving telegraph lines use:

a. simplex lines

b. wideband channel

c. narrowband channel

d. dialed service

Question 5:

A communications device that combines transmissions from several I/O devices into one line is a 

a. concentrator

b. modifier

c. multiplexer

d. full-duplex line

Question 6:

How much power (roughly) a light emitting diode can couple into an optical fiber?

a. 100 microwatts

b. 440 microwatts

c. 100 picowatts

d. 10 miliwatts

Question 7:

The synchronous modems are more costly than the asynchronous modems because

a. they produce large volume of data

b. they contain clock recovery circuits

c. they transmit the data with stop and start bits

d. they operate with a larger bandwidth

e. none of above

Question 8:

Which of the following statement is correct?

a. terminal section of a synchronous modem contains the scrambler

b. receiver section of a synchronous modem contains the scrambler

c. transmission section of a synchronous modem contains the scrambler

d. control section of a synchronous modem contains the scrambler

e. none of the above

Question 9:

In a synchronous modem, the digital-to-analog converter transmits signal to the 

a. equilizer

b. modulator

c. demodulator

d. terminal

e. none of aobve

Question 10:

Which of the following communications lines is best suited to interactive processing applications?

a. narrow band channel

b. simplex lines

c. full duplex lines

d. mixed band channels

Answers

1. c
2. b
3. c
4. c
5. c
6. a
7. b
8. c
9. a
10. c
Question:1
A remote batch-processing operation in which data is solely input to a central computer would require
a. telegraphp line
b. simplex lines
c. mixed bad channel
d. all of above

Question 2:
A band is always equivalent to
a. a byte
b. a bit
c. 100 bits
d. none of above

Question 3:
The loss in signal power as light travels down the fiber is called
a. attenuation
b. progragation
c. scattering
d. interruption

Question 4:
Avalanche photodiode receivers can detect bits of transmitted data by receiving
a. 100 photons
b. 200 photons
c. 2000 photons
d. 300 photons

Question 5:
Communiction circuits that transmit data in both directions but not at the same time are operating in
a. a simplex mode
b. a half duplex mode
c. a full duplex mode
d. an asynchronous mode

Question 6:
An example of a medium speed, switched communications service is
a. series 1000
b. data phone 50
c. DDD
d. All of the above

Question 7:
In communication satellite, multiple repeaters are known as
a. detector
b. modulator
c. stations
d. transponders

Question 8:
While transmitting odd-parity coded symbols, the number of zeros in each symbol is
a. odd
b. even
c. a and b both
d. unknown

Question 9:
Data communications monitors available on the software marked include
a. ENVIRON/1
b. TOTAL
c. BPL
d. Telnet

Question 10:
An example of an analog communication method is
a. laser beam
b. microwave
c. voice grade telephone line
d. all of the above
1. b
2. d
3. a
4. b
5. b
6. c
7. d
8. d
9. a
10. d

Question:1

Number of bits per symbol used in Baudot code is

a. 7

b. 5

c. 8

d. 9

Question 2:

What is the main difference between DDCMP and SDLC?

a. DDCMP does not need special hardware to final the beginning of a message

b. DDCMP has a message header

c. SDLC has a IP address

d. SDLC does not use CRC

Question 3:

An example of digital, rather than analog, communication is

a. DDD

b. DDS

c. WATS

d. DDT

Question 4:

Terminals are required for 

a. real-time, batch processing & time-sharing

b. real time, time-sharing & distributed message processing

c. real time, distributed processing & manager inquiry

d. real-time,  time sharing & message switching

Question 5:

The receive equilizer reduces delay distortions using a

a. tapped delay lines

b. gearshift

c. descrambler

d. difference engine

Question 6:

Ina synchronous modem, the receive equilizer is known as

a. adaptive equilizer

b. impariment equilizer

c. statistical equilizer

d. compromise equilizer 

Question 7:

The channel in the data communication model can be

a. postal mail services

b. telephone lines

c. radio lines

d. any of the above

Question 8:

A data terminal serves as an

a. Effector

b. sensor

c. both a and b

d. neither a nor b

Question 9:

Which of the following transmission systems provide the highest data rate to in individual device?

a. computer bus

b. telephone lines

c. voice and mode

d. lease lines

Question 10:

A protocol is a set of rules governing a time sequence of events that must take place

a. between peers

b. between an interface

c. between modems

d. across an interface

1. b

2. a

3. b

4. d

5. a

6. a

7. d

8. c

9. a

10. a