WorksheetsNWC 41-60
Total questions: 20
Worksheet time: 11mins
Which of following statements are true for single-bit parity error detection?
It can detect all single bit errors in an information frame
It can detect all double bit errors in an information frame
It can detect all tripe bit errors in an information frame
None of the above
Which of following statements are true for two-dimensional parity error detection?
It can detect all single bit errors in an information frame
It can correct all single bit errors in an information frame
It can detect all double bit errors in an information frame
All of the above
Assume bit errors occur at random. If each bit has 50% probability to be in error by transmission. What is the probability of a four-bit frame to be in error by transmission?
1/4
1/8
1/16
None of the above
What is the binary sequence that corresponds to polynomial code X^3 + x^2 + 1?
1110
0111
1101
111
Block codes are generated using _____.
Generator matrix
Generator polynomial
Both of the mentioned
None of the mentioned
Which of the following is true for two-dimensional parity check
Arrange information in rows
More parity bit to improve coverage
Arrange information in columns
Add multiple parity bits to each column
Polynomial codes are implemented using shift register circuits
t
f
Using Euclidean Division, what will be the remainder of 70 by 999 where 70 is the divisor and 999 is the dividend
17
14
21
19
In networks where errors are infrequent, which approach is favored for efficiency?
Hop-by-hop approach
End-to-end approach
Either one of the above
Neither one of the above
Which of the following statements is true about the stop-and-wait ARQ protocol?
Stop-and-wait is only efficient if the link delay-bandwidth product is large
Stop-and-wait is only efficient if the link delay-bandwidth product is small
Stop-and-wait is only efficient if the link bandwidth is lowStop-and-wait is only efficient if the link bandwidth is low
Stop-and-wait is only efficient if the link bandwidth is high
Consider a situation where an interactive application produces a packet to send each keystroke from the client and the server echoes each keystroke that it receives from the client. Which of following strategies for sending ACK frames in a Go-Back-N is appropriate for the situation?
send an ACK frame immediately after each frame is received
send an ACK frame after every other frame is received
send an ACK frame when the next piggyback opportunity arises
Any one of the above
Consider a bulk data transfer application where a server sends a large file that is segmented in a number of full-size packets that are to be transferred to the client. Assume the channel has a low probability of error. Which of following strategies for sending ACK frames in a Go-Back-N is appropriate for the situation?
send an ACK frame when the next piggyback opportunity arises
send an ACK frame immediately after each frame is received
send an ACK frame after every other frame is received
Any one of the above
ARQ protocols combine error detection, retransmission and sequence numbering to provide reliability
t
f
A service model specifies a level of performance that can be expected in the transfer of information.
t
f
A service offered at a given layer can include which of the following feature(s)
Sequencing
Reliability
Timing
All of the above
Digital communication technologies may introduce errors in communication, which of the following can be used to provide reliable communication
TCP
DNS
UDP
HDLC
Ensuring that information is not altered during transfer is associated with
Authentication
Confidentiality
Integrity
Availability
Given 3 bits for sequence numbers, what is the maximum sliding window size at the receiver in Go Back 3 ARQ?
3
7
8
None of the above
Given 3 bits for sequence numbers in Selective Repeat ARQ. If the sender already set the sliding window size to be 4, what is the maximum sliding window size at the receiver?
3
8
7
None of the above
In the scenario above, what should be the value of frame number y at receiver B?
3
8
7
None of the above
