Computer Networks Test 2

Question 1
2 / -0.33

In ethernet, when Manchester encoding is used, baud rate is 10⁶ b/s. Find the bit rate?

A
10⁶ B/s

B
10⁶ b/s

C
5 × 10⁵ B/s

D
5 × 10⁵ b/s

Question 2
2 / -0.33

Which is/are the Application layer protocol?

A
FTP

B
SMTP

C
OSPF

D
IMAP

Question 3
2 / -0.33

The address of a class A host is to be split into subnets with a 14-bit subnet number. The remaining bits in host id is x and the maximum number of hosts in each subnet is y. What is the value of x + y?

A
1032-1032

B
10324-10321

C
10327-10326

D
10329-10322

Question 4
2 / -0.33

A computer uses the following sequence numbers
0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,0,1,2,3,4……
What are the senders and receivers window size is possible in SR protocol?

A
9,7

B
15,1

C
8,8

D
9,8

Question 5
2 / -0.33

Let the size of congestion window of a TCP connection be 64 KB when a timeout occurs. The round-trip time is 50 milliseconds and the maximum segment size is 2 KB. The time taken (in milliseconds) by the TCP connection to get 64 KB congestion window is

A
900

B
1000

C
1100

D
1200

Question 6
2 / -0.33

Which of the following statement is correct about HTTP?

A
HTTP version 1.1 specifies a non – persistent connection by default.

B
HTTP uses the services of TCP on port 80

C
HTTP uses the services of UDP on port 80

D
In non-persistent connection, one TCP connection is made for each request/response

Question 7
2 / -0.33

Consider the following destination address of standard Ethernet
43:10:1B:2D:06:EE
What is the type of the above given destination Ethernet address?

A
Unicast

B
Multicast

C
Broadcast

D
None of these

Question 8
2 / -0.33

A pure ALOHA network transmits 400-bit frames on a shared channel of 400 kbps. What is the maximum throughput(in frames) if the system (all stations together) produces 500 frames per second?

A
91-91

B
914-911

C
917-916

D
919-912

Question 9
2 / -0.33

Consider the following set of statements: Which of the above statements is/are true?

A
The transport layer can be either connectionless or connection-oriented.

B
The network layer is responsible for packet forwarding including routing through intermediate routers

C
The data link layer defines the direction of transmission between two devices.

D
The physical layer is concerned with the connection of the devices to the media.

Question 10
2 / -0.33

If bandwidth of the link is 2Gbps and frame size is 1000 bits. Distance between two nodes is 6km and velocity of signal in medium is 3 × 10⁸ m/sec and it is given that channel is error free and pure sliding window protocol is used, then what is the sender window size?

A
40

B
60

C
80

D
50

Question 11
2 / -0.33

Consider a sender sends data using stop and wait protocol to the receiver. If the receiver wants 31 packets and every 4^th packet is lost. What is the total number of packets sent by the sender?

A
41-41

B
414-411

C
417-416

D
419-412

Question 12
2 / -0.33

Which of the following statements are true?
(a) Three broad categories of Networks are:
(i) Circuit Switched Networks
(ii) Packet Switched Networks
(iii) Message Switched Networks
(b) Circuit Switched Network resources need not be reserved during the set up phase.
(c) In packet switching there is no resource allocation for packets.

A
(a) and (b) only

B
(b) and (c) only

C
(a) and (c) only

D
(a), (b) and (c)

Question 13
2 / -0.33

Consider three machines X, Y, and Z with IP address 200.20.15.3, 200.20.15.1, and 200.20.15.2 respectively. The subnet mask is set to 255.255.255.254 for all the three machines. Which one of the following is/are true?

A
Y and Z belong to the different subnet

B
X and Y belong to the same subnet

C
X and Z belong to the same subnet

D
X, Y and Z belong to the different subnet

Question 14
2 / -0.33

Consider two hosts S and R connected directly by a link. A link has a transmission speed of 10⁷ bits/sec. It uses data packets of size 400 bytes. Data needed to transmitted is 400 bytes. Length of the link is 600 km and the propagation speed are 3 × 10⁸ meter per second. T is the transmission delay and P is the propagation delay. The propagation delay in millisecond and transmission delay in microsecond respectively are

A
2 and 320

B
2000 and 320

C
320 and 2

D
2000 and 0.32

Question 15
2 / -0.33

There are 5 stations in a slotted LAN. Each station attempts to transmit with a probability 0.6 in each time slot. What is the probability that only one station transmits in a given time slot?

A
0.7680

B
0.0768

C
0.0568

D
0.5680

Question 16
2 / -0.33

A linear Hamming code is used to map 4-bit messages to 7-bit code words. The encoder mapping is linear. If the message 0001 is mapped to the code word 0000111, and the message 0011 is mapped to the code word 1100110, then the message 0010 is mapped to

A
0010011

B
1100001

C
1111000

D
1111111

Question 17
2 / -0.33

Consider host A sends a UDP datagram containing 16060 bytes of user data to host B over an Ethernet LAN. Ethernet MTU is 1500 byte. Size of the IP header is 40 byte and the size of the UDP header is 8 bytes. Which of the following is/are true about the number of fragments transmitted and contents of the offset field in the last fragment?

A
number of fragments transmitted = 11

B
offset field in the last fragment = 2002

C
number of fragments transmitted = 12

D
offset field in the last fragment = 1820

Question 18
2 / -0.33

Which of the following statements is/are true?
I. Bridge reduces collision domain
II. Bridge reduces broadcast domain
III. CSMA/CD is suitable for a high propagation delay network like satellite network

A
Only I

B
I and II

C
I and III

D
II and III

Question 19
2 / -0.33

Consider the routing table shown below. A router can deliver the packets directly over interface 0 and 1 or it can forward to router R2, R3 and R4.
Subnet number
Subnet mask
Next Hop
128.100.40.128
255.255.255.128
Interface 0
128.96.40.0
255.255.255.128
Interface 1
128.100.40.0
255.255.255.128
R2
128.100.39.36
255.255.255.192
R3
Default

R4

What does the router with packet addressed to 128.100.40.36?

A
Interface

B
R3

C
R2

D
R4

Question 20
2 / -0.33

Let host A sends a file a size of 2200 byte to host B through routers R1, R2, R3, R4 and R5 respectively. Each packet contains 110 bytes of header information along with the user data. Assume that the bandwidth of each link is 10⁶ B/s. File is split into 20 equal parts, and these packets are transmitted from A to B. Consider only transmission time and ignore processing, queuing and propagation delays also no error in transmission. What is the time taken by host A to send the complete file to host B?

A
13.2

B
7.5

C
5.5

D
3.3

Question 21
2 / -0.33

Consider a long-lived TCP session with an end-to-end bandwidth 2 GB/s. The session starts with a sequence number of 3465. The minimum time (in seconds correct up to two decimal places) before this sequence number can be used again is _____

A
2.14-2.15

B
2.144-2.151

C
2.147-2.156

D
2.149-2.152

Submit Test

Subnet number	Subnet mask	Next Hop
128.100.40.128	255.255.255.128	Interface 0
128.96.40.0	255.255.255.128	Interface 1
128.100.40.0	255.255.255.128	R2
128.100.39.36	255.255.255.192	R3
Default		R4

Computer Networ...

Question 1

106 B/s

106 b/s

5 × 105 B/s

5 × 105 b/s

Question 2

FTP

SMTP

OSPF

IMAP

Question 3

1032-1032

10324-10321

10327-10326

10329-10322

Question 4

9,7

15,1

8,8

9,8

Question 5

900

1000

1100

1200

Question 6

HTTP version 1.1 specifies a non – persistent connection by default.

HTTP uses the services of TCP on port 80

HTTP uses the services of UDP on port 80

In non-persistent connection, one TCP connection is made for each request/response

Question 7

Unicast

Multicast

Broadcast

None of these

Question 8

91-91

914-911

917-916

919-912

Question 9

The transport layer can be either connectionless or connection-oriented.

The network layer is responsible for packet forwarding including routing through intermediate routers

The data link layer defines the direction of transmission between two devices.

The physical layer is concerned with the connection of the devices to the media.

Question 10

40

60

80

50

Question 11

41-41

414-411

417-416

419-412

Question 12

(a) and (b) only

(b) and (c) only

(a) and (c) only

(a), (b) and (c)

Question 13

Y and Z belong to the different subnet

X and Y belong to the same subnet

X and Z belong to the same subnet

X, Y and Z belong to the different subnet

Question 14

2 and 320

2000 and 320

320 and 2

2000 and 0.32

Question 15

0.7680

0.0768

0.0568

0.5680

Question 16

0010011

1100001

1111000

10⁶ B/s

10⁶ b/s

5 × 10⁵ B/s

5 × 10⁵ b/s

offset field in the last fragment = 1820