• Courses
  • Tutorials
  • Jobs
  • Practice
  • Contests

50 Computer Networks MCQs with Answers

Question 1

Consider a network using the pure ALOHA medium access control protocol, where each frame is of length 1,000 bits. The channel transmission rate is 1 Mbps (=106 bits per second). The aggregate number of transmissions across all the nodes (including new frame transmissions and retransmitted frames due to collisions) is modelled as a Poisson process with a rate of 1,000 frames per second. Throughput is defined as the average number of frames successfully transmitted per second. The throughput of the network (rounded to the nearest integer) is ______________ .
  • 130 to 140
  • 140 to 150
  • 120 to 130
  • 100 to 110

Question 2

Consider the cyclic redundancy check (CRC) based error detecting scheme having the generator polynomial X3+X+1. Suppose the message m4m3m2m1m0 = 11000 is to be transmitted. Check bits c2c1c0 are appended at the end of the message by the transmitter using the above CRC scheme. The transmitted bit string is denoted by m4m3m2m1m0c2c1c0. The value of the checkbit sequence c2c1c0 is
  • 101
  • 110
  • 100
  • 111

Question 3

Consider a link with packet loss probability of 0.2. What is the expected number of transmissions it would take to transfer 200 packets given that the stop and wait protocol is used?
  • 125
  • 250
  • 225
  • 150

Question 4

Assume that Source S and Destination D are connected through an intermediate router R. How many times a packet has to visit the network layer and data link layer during a transmission from S to D?
  • Network layer – 4 times, Data link layer – 4 times
  • Network layer – 4 times, Data link layer – 6 times
  • Network layer – 2 times, Data link layer – 4 times
  • Network layer – 3 times, Data link layer – 4 times

Question 5

An Ethernet frame that is less than the IEEE 802.3 minimum length of 64 octets is called

  • Short frame

  • Small frame

  • Mini frame

  • Runt frame

Question 6

Which of the following protocols is an application layer protocol that establishes, manages and terminates multimedia sessions ?
  • Session Maintenance Protocol
  • Real - time Streaming Protocol
  • Real - time Transport Control Protocol
  • Session Initiation Protocol

Question 7

What is the size of the ‘total length’ field in IPv4 datagram?
  • 4 bit
  • 8 bit
  • 16 bit
  • 32 bit

Question 8

A packet filtering firewall can
  • deny certain users from accessing a service
  • block worms and viruses from entering the network
  • disallow some files from being accessed through FTP
  • block some hosts from accessing the network

Question 9

Consider the set of activities related to e-mail A : Send an e-mail from a mail client to mail server B : Download e-mail headers from mail box and retrieve mails from server to a cache C : Checking e-mail through a web browser The application level protocol used for each activity in the same sequence is

Question 10

What is one advantage of setting up a DMZ(Demilitarized Zone) with two firewalls?

  • You can control where traffic goes in the three networks

  • You can do stateful packet filtering

  • You can do load balancing

  • Improve network performance

There are 50 questions to complete.

Last Updated :
Take a part in the ongoing discussion