Question 1

What does the data link layer do? What are its primary responsibilities? Where does the data link layer sit in terms of the simplified five layer network model?

Accepted Answer

The data link layer is responsible for the reliable transmission of data across a physical network link. Its primary responsibilities include framing, addressing, error detection and correction, and flow control.

In terms of the simplified five layer network model, the data link layer sits between the physical layer and the network layer. It is responsible for providing a reliable link between two directly connected nodes, ensuring that data is transmitted accurately and efficiently. This layer also handles the physical addressing of devices on the network and manages the flow of data between them. Overall, the data link layer plays a crucial role in ensuring the smooth and reliable transmission of data within a network.

Question 2

Which of the following media is least susceptible to noise?

Accepted Answer

A) fiber optic cable 
B) coaxial cable 
C) twisted pair 
D) unshielded twisted pair 
E) shielded twisted pair 
A) fiber optic cable 
B) coaxial cable 
C) twisted pair 
D) unshielded twisted pair 
E) shielded twisted pair A

Question 3

Parity checking can only detect an error when an even number of bits are switched.

Accepted Answer

A) True 
 B)False  False

Question 4

With __________ ARQ, the sender pauses for a response from the receiver to alter each message or packet of data.

Accepted Answer

A) open window 
B) halt and be recognized HBR) 
C) sliding window 
D) stop and wait 
E) continuous 
A) open window 
B) halt and be recognized HBR) 
C) sliding window 
D) stop and wait 
E) continuous

Question 5

The distance between repeaters or amplifiers on a telephone circuit is determined by the amount of power gained per unit length of the transmission.

Accepted Answer

A) True 
 B)False

Question 6

In communication protocols, _________ are used to convey the user's meaning.

Accepted Answer

A) information bits 
B) overhead bits 
C) stop bits 
D) start bits 
E) flag bits 
A) information bits 
B) overhead bits 
C) stop bits 
D) start bits 
E) flag bits

Question 7

Which of the following is not a type of synchronous protocol?

Accepted Answer

A) SDLC 
B) VT100 
C) HDLC 
D) Ethernet 
E) PPP 
A) SDLC 
B) VT100 
C) HDLC 
D) Ethernet 
E) PPP

Question 8

________ is the process of sending a signal to a client that gives its permission to transmit or asks it to receive.

Accepted Answer

A) Contention 
B) Polling 
C) Pooling 
D) Carrier sense 
E) CRC 
A) Contention 
B) Polling 
C) Pooling 
D) Carrier sense 
E) CRC

Question 9

Which of the following is true with respect to the data link layer?

Accepted Answer

A) It accepts streams of bits from the application layer. 
B) It is responsible for encoding the bit-stream as a series of electronic voltages. 
C) It performs error detection. 
D) It performs routing functions. 
E) It organizes data from the physical layer and passes these coherent messages directly to the application layer. 
A) It accepts streams of bits from the application layer. 
B) It is responsible for encoding the bit-stream as a series of electronic voltages. 
C) It performs error detection. 
D) It performs routing functions. 
E) It organizes data from the physical layer and passes these coherent messages directly to the application layer.

Question 10

_____________ is an effective way to prevent impulse noise, cross talk, and intermodulation noise.

Accepted Answer

A) Shielding wires 
B) Adding fluorescent lights 
C) Adding repeaters to a circuit 
D) Adding amplifiers to a circuit 
E) Shorting a circuit 
A) Shielding wires 
B) Adding fluorescent lights 
C) Adding repeaters to a circuit 
D) Adding amplifiers to a circuit 
E) Shorting a circuit

Question 11

Describe from a high level perspective the packet layout for SDLC, Ethernet, and PPP.

Accepted Answer

The packet layout for SDLC (Synchronous

Question 12

How does forward error correction work? How is it different from other error correction methods? Under what circumstances is forward error correction desirable? What is one type of forward error correction by name? Given a diagram like that in the text of forward error correction, be able to explain how the system works.

Accepted Answer

Forward error correction (FEC) is a meth

Question 13

Impulse noise is caused by the thermal agitation of electrons.

Accepted Answer

A) True 
 B)False

Question 14

__________can obliterate a group of bits, causing a burst error.

Accepted Answer

A) Cross-talk 
B) Attenuation 
C) Impulse noise 
D) Intermodulation noise 
E) White noise 
A) Cross-talk 
B) Attenuation 
C) Impulse noise 
D) Intermodulation noise 
E) White noise

Question 15

Data transmission errors are typically uniformly distributed in time.

Accepted Answer

A) True 
 B)False

Question 16

Cyclical redundancy check is one of the most popular polynomial error-checking schemes.

Accepted Answer

A) True 
 B)False

Question 17

Undesirable stray electrical voltage can cause data communication errors.

Accepted Answer

A) True 
 B)False

Question 18

Media access controls refer to the need to control when computers transmit.

Accepted Answer

A) True 
 B)False

Question 19

Stop-and-wait ARQ uses ___________ type of data flow.

Accepted Answer

A) full simplex 
B) half complex 
C) full duplex 
D) half duplex 
E) full complex 
A) full simplex 
B) half complex 
C) full duplex 
D) half duplex 
E) full complex

Question 20

Briefly describe how even parity and odd parity work.Give an example of even parity with a 7-bit ASCII code, for the following: 0110110, using a 0 start bit and a 1 stop bit.

Accepted Answer

Even parity and odd parity are methods u

What does the data link layer do? What are its primary responsibilities? Where does the data link layer sit in terms of the simplified five layer network model?

Which of the following media is least susceptible to noise?

Parity checking can only detect an error when an even number of bits are switched.

With __________ ARQ, the sender pauses for a response from the receiver to alter each message or packet of data.

The distance between repeaters or amplifiers on a telephone circuit is determined by the amount of power gained per unit length of the transmission.

In communication protocols, _________ are used to convey the user's meaning.

Which of the following is not a type of synchronous protocol?

________ is the process of sending a signal to a client that gives its permission to transmit or asks it to receive.

Which of the following is true with respect to the data link layer?

_____________ is an effective way to prevent impulse noise, cross talk, and intermodulation noise.

Describe from a high level perspective the packet layout for SDLC, Ethernet, and PPP.

Impulse noise is caused by the thermal agitation of electrons.

__________can obliterate a group of bits, causing a burst error.

Data transmission errors are typically uniformly distributed in time.

Cyclical redundancy check is one of the most popular polynomial error-checking schemes.

Undesirable stray electrical voltage can cause data communication errors.

Media access controls refer to the need to control when computers transmit.

Stop-and-wait ARQ uses ___________ type of data flow.

Briefly describe how even parity and odd parity work.Give an example of even parity with a 7-bit ASCII code, for the following: 0110110, using a 0 start bit and a 1 stop bit.

Introduction to Data Communications

Application Layer

Physical Layer

Network and Transport Layers

Network Design

Wired and Wireless Local Area Networks

Backbone Networks

Wide Area Networks

The Internet

Network Security

Network Management

Filters

Exam 4: Data Link Layer

What does the data link layer do? What are its primary responsibilities? Where does the data link layer sit in terms of the simplified five layer network model?

Which of the following media is least susceptible to noise?

Parity checking can only detect an error when an even number of bits are switched.

With __________ ARQ, the sender pauses for a response from the receiver to alter each message or packet of data.

The distance between repeaters or amplifiers on a telephone circuit is determined by the amount of power gained per unit length of the transmission.

In communication protocols, _________ are used to convey the user's meaning.

Which of the following is not a type of synchronous protocol?

________ is the process of sending a signal to a client that gives its permission to transmit or asks it to receive.

Which of the following is true with respect to the data link layer?

_____________ is an effective way to prevent impulse noise, cross talk, and intermodulation noise.

Describe from a high level perspective the packet layout for SDLC, Ethernet, and PPP.

Impulse noise is caused by the thermal agitation of electrons.

__________can obliterate a group of bits, causing a burst error.

Data transmission errors are typically uniformly distributed in time.

Cyclical redundancy check is one of the most popular polynomial error-checking schemes.

Undesirable stray electrical voltage can cause data communication errors.

Media access controls refer to the need to control when computers transmit.

Stop-and-wait ARQ uses ___________ type of data flow.

Briefly describe how even parity and odd parity work.Give an example of even parity with a 7-bit ASCII code, for the following: 0110110, using a 0 start bit and a 1 stop bit.

Introduction to Data Communications

Application Layer

Physical Layer

Network and Transport Layers

Network Design

Wired and Wireless Local Area Networks

Backbone Networks

Wide Area Networks

The Internet

Network Security

Network Management

Filters