1
In the simplex stop-and-wait protocol for an error-free channel, the sender
Correct Answer
sends one frame and waits for an acknowledgement
☑ MCQ PRACTICE
Computer Networks Unit 2
Practice objective questions for quick revision and examination preparation. Try answering each question before revealing the answer.
Computer Networks MCQs - Unit 2
2
A stop-and-wait protocol for a noisy channel needs
Correct Answer
a timer and sequence numbers
3
PAR stands for
Correct Answer
Positive Acknowledgement with Retransmission
4
The one-bit sliding window protocol has a window size of
Correct Answer
1
5
The receiver window size in Go-Back-N is
Correct Answer
1
6
With n-bit sequence numbers, the maximum sender window size in Go-Back-N is
Correct Answer
2ⁿ − 1
7
With n-bit sequence numbers, the maximum window size in Selective Repeat is
Correct Answer
2ⁿ⁻¹
8
In Go-Back-N, when a frame is damaged, the sender retransmits
Correct Answer
that frame and all the frames that follow it
9
In Selective Repeat, when a frame is damaged, the sender retransmits
Correct Answer
only the damaged frame
10
Piggybacking means
Correct Answer
attaching an acknowledgement to an outgoing data frame
11
HDLC is a
Correct Answer
bit-oriented data link protocol
12
PPP is mainly used for
Correct Answer
point-to-point links such as dial-up Internet access
13
The channel allocation problem deals with
Correct Answer
how to share a single broadcast channel among competing users
14
The maximum throughput of pure ALOHA is about
Correct Answer
18.4%
15
The maximum throughput of slotted ALOHA is about
Correct Answer
36.8%
16
The vulnerable period of a frame in pure ALOHA is
Correct Answer
two frame times
17
In CSMA, a station
Correct Answer
listens to the channel before transmitting
18
In 1-persistent CSMA, a station that finds the channel idle
Correct Answer
transmits immediately
19
CSMA/CD is used in
Correct Answer
classic Ethernet
20
CSMA/CA is used in
Correct Answer
wireless LANs (IEEE 802.11)
21
Which of the following is a collision-free protocol?
Correct Answer
Bit-map protocol
22
The hidden terminal problem occurs in
Correct Answer
wireless LANs
23
A learning bridge builds its forwarding table using
Correct Answer
backward learning
24
Bridges use a spanning tree to
Correct Answer
avoid loops in the network
25
Data link layer switching is done by
Correct Answer
bridges and switches
Fill in the Blanks
26
In stop-and-wait, the sender waits for an ______ before sending the next frame.
Correct Answer
acknowledgement
27
PAR stands for Positive Acknowledgement with ______.
Correct Answer
Retransmission
28
The receiver window size in Go-Back-N is ______.
Correct Answer
1
29
With n-bit sequence numbers, the maximum sender window in Go-Back-N is ______.
Correct Answer
2ⁿ − 1
30
With n-bit sequence numbers, the maximum window size in Selective Repeat is ______.
Correct Answer
2ⁿ⁻¹
31
Attaching an acknowledgement to an outgoing data frame is called ______.
Correct Answer
piggybacking
32
The maximum throughput of pure ALOHA is about ______.
Correct Answer
18.4%
33
The maximum throughput of slotted ALOHA is about ______.
Correct Answer
36.8%
34
The vulnerable period of pure ALOHA is ______ frame times.
Correct Answer
two
35
CSMA/CD stands for Carrier Sense Multiple Access with Collision ______.
Correct Answer
Detection
36
CSMA/CA is used in ______ LANs.
Correct Answer
wireless
37
In the ______ protocol, stations announce their wish to transmit in contention slots.
Correct Answer
bit-map
38
______ is a bit-oriented data link protocol.
Correct Answer
HDLC
39
PPP stands for ______ Protocol.
Correct Answer
Point-to-Point
40
Bridges learn the location of stations using ______ learning.
Correct Answer
backward