Question 1

Asynchronous transmission:

Accepted Answer

A) is used to transmit each character simultaneously with all other characters 
B) has a pre-determined, fixed time between sending characters 
C) is typically used on multipoint half duplex circuits 
D) uses a continuous series of start bits as an idle signal 
E) each character is transmitted independently of all other characters 
A) is used to transmit each character simultaneously with all other characters 
B) has a pre-determined, fixed time between sending characters 
C) is typically used on multipoint half duplex circuits 
D) uses a continuous series of start bits as an idle signal 
E) each character is transmitted independently of all other characters

Question 2

In a _________ , more than one data bit is changed by the error-causing condition.

Accepted Answer

A) burst error 
B) data rate shift 
C) Trellis-coded modulation 
D) uniform distribution 
E)  amplitude key shift 
A) burst error 
B) data rate shift 
C) Trellis-coded modulation 
D) uniform distribution 
E)  amplitude key shift

Question 3

With __________ ARQ, the sender immediately sends the next message or packet of data.

Accepted Answer

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

Question 4

Describe how MAC address filtering works.

Accepted Answer

MAC address filtering is a security feat

Question 5

How do amplifiers differ from repeaters?

Accepted Answer

Amplifiers and repeaters are both device

Question 6

The probability of detecting an error, provided that one has occurred, using cyclic redundancy checking is about:

Accepted Answer

A) 75% 
B) 0% 
C) exactly 100% 
D) 50% 
E) > 99% 
A) 75% 
B) 0% 
C) exactly 100% 
D) 50% 
E) > 99%

Question 7

Which of the following is true about roll call polling?

Accepted Answer

A) It can not be modified to increase priority of clients or terminals. 
B) It does not require a server or host or special device that performs the polling. 
C) It is also called token passing. 
D) It is a type of contention approach to media access control. 
E) It typically involves some waiting because the server has to wait for a response from the polled client or terminal. 
A) It can not be modified to increase priority of clients or terminals. 
B) It does not require a server or host or special device that performs the polling. 
C) It is also called token passing. 
D) It is a type of contention approach to media access control. 
E) It typically involves some waiting because the server has to wait for a response from the polled client or terminal.

Question 8

The primary source of error in data communications is:

Accepted Answer

A) echoes 
B) intermodulation noise 
C) spikes 
D) attenuation 
E) cross-talk 
A) echoes 
B) intermodulation noise 
C) spikes 
D) attenuation 
E) cross-talk

Question 9

Controlled access MAC approaches work better in a large network with high usage.

Accepted Answer

A) True 
 B)False

Question 10

The data link layer accepts messages from the network layer and controls the hardware that transmits them.

Accepted Answer

A) True 
 B)False

Question 11

Which of the following is not an error detection method used in the data link layer?

Accepted Answer

A) parity checking 
B) cyclic redundancy checking 
C) CRC-32 
D) pulse code checking 
E) odd parity 
A) parity checking 
B) cyclic redundancy checking 
C) CRC-32 
D) pulse code checking 
E) odd parity

Question 12

When we amplify the signal on an analog circuit, we also amplify any noise that is present on the circuit.

Accepted Answer

A) True 
 B)False

Question 13

Media access control:

Accepted Answer

A) is not very important in point-to-point with full duplex configuration 
B) is not very important in local area networks 
C) is not very important in a point-to-point with a half duplex configuration 
D) is not very important in a multipoint configuration 
E) does not control when computers transmit 
A) is not very important in point-to-point with full duplex configuration 
B) is not very important in local area networks 
C) is not very important in a point-to-point with a half duplex configuration 
D) is not very important in a multipoint configuration 
E) does not control when computers transmit

Question 14

What is transparency?

Accepted Answer

Transparency, in a general context, refe

Question 15

______________ controls errors by detecting and correcting them at the receiving end without retransmission of the original message.

Accepted Answer

A) Hamming code 
B) Huffman encoding 
C) Front end processing 
D) Wave division multiplexing 
E) Hub polling 
A) Hamming code 
B) Huffman encoding 
C) Front end processing 
D) Wave division multiplexing 
E) Hub polling

Question 16

What is transmission efficiency? How do information bits differ from overhead bits? What are three issues which might effect packet throughput rates? Which is better for file transfer, large packet sizes or small packet sizes?

Accepted Answer

Transmission efficiency refers to the ab

Question 17

Describe three approaches to detecting errors, including how they work, the probability of detecting an error, and any other benefits or limitations.

Accepted Answer

1. Checksums: This approach involves add

Question 18

Optical media is:

Accepted Answer

A) more likely to suffer from noise than electrical media 
B) has about the same likelihood of suffering from noise as electrical media 
C) has about the same likelihood of suffering from noise as coaxial cable 
D) less likely to suffer from noise than electrical media 
E) more prone to noise than twisted pair media 
A) more likely to suffer from noise than electrical media 
B) has about the same likelihood of suffering from noise as electrical media 
C) has about the same likelihood of suffering from noise as coaxial cable 
D) less likely to suffer from noise than electrical media 
E) more prone to noise than twisted pair media

Question 19

Polling is the process of permitting all clients to transmit or receive at any time.

Accepted Answer

A) True 
 B)False

Question 20

For effective error detection and correction, extra error detection "data" must be included with each message

Accepted Answer

A) True 
 B)False

Asynchronous transmission:

In a _________ , more than one data bit is changed by the error-causing condition.

With __________ ARQ, the sender immediately sends the next message or packet of data.

Describe how MAC address filtering works.

How do amplifiers differ from repeaters?

The probability of detecting an error, provided that one has occurred, using cyclic redundancy checking is about:

Which of the following is true about roll call polling?

The primary source of error in data communications is:

Controlled access MAC approaches work better in a large network with high usage.

The data link layer accepts messages from the network layer and controls the hardware that transmits them.

Which of the following is not an error detection method used in the data link layer?

When we amplify the signal on an analog circuit, we also amplify any noise that is present on the circuit.

Media access control:

What is transparency?

______________ controls errors by detecting and correcting them at the receiving end without retransmission of the original message.

What is transmission efficiency? How do information bits differ from overhead bits? What are three issues which might effect packet throughput rates? Which is better for file transfer, large packet sizes or small packet sizes?

Describe three approaches to detecting errors, including how they work, the probability of detecting an error, and any other benefits or limitations.

Optical media is:

Polling is the process of permitting all clients to transmit or receive at any time.

For effective error detection and correction, extra error detection "data" must be included with each message

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

Asynchronous transmission:

In a _________ , more than one data bit is changed by the error-causing condition.

With __________ ARQ, the sender immediately sends the next message or packet of data.

Describe how MAC address filtering works.

How do amplifiers differ from repeaters?

The probability of detecting an error, provided that one has occurred, using cyclic redundancy checking is about:

Which of the following is true about roll call polling?

The primary source of error in data communications is:

Controlled access MAC approaches work better in a large network with high usage.

The data link layer accepts messages from the network layer and controls the hardware that transmits them.

Which of the following is not an error detection method used in the data link layer?

When we amplify the signal on an analog circuit, we also amplify any noise that is present on the circuit.

Media access control:

What is transparency?

______________ controls errors by detecting and correcting them at the receiving end without retransmission of the original message.

What is transmission efficiency? How do information bits differ from overhead bits? What are three issues which might effect packet throughput rates? Which is better for file transfer, large packet sizes or small packet sizes?

Describe three approaches to detecting errors, including how they work, the probability of detecting an error, and any other benefits or limitations.

Optical media is:

Polling is the process of permitting all clients to transmit or receive at any time.

For effective error detection and correction, extra error detection "data" must be included with each message

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