Wednesday, 8 February 2017

NIELIT A Level Solved Paper January-2011

January, 2011
A9-R4: DATA COMMUNICATION & NETWORKING TECHNOLOGIES

PART ONE
(Answer all the questions)

1. Each question below gives a multiple choice of answers. Choose the most appropriate one and enter in the “tear-off” answer sheet attached to the question paper, following instructions therein. (1x10)
1.1 Which of the following technique uses four twisted-pair cables that connect each station to a
common hub?
A) 10Base-2
B) 10Base-5
C) 10Base-T
D) 10Base-F
1.2 Sliding window is a technique for ________.
A) line discipline
B) error control
C) flow control
D) session management
1.3 What is a second-generation cellular phone system that is a digital version of AMPS?
A) GSM
B) CDMA
C) DSSA
D) D-AMPS
1.4 In TCP, the path ________.
A) upto destination is allocated before the transmission of message begins
B) upto next intermediate node is allocated before the transmission of message begins
C) to be followed depends on the length of message
D) none of the above
A9-R4 Page 2 of 5 January, 2011
1.5 Which of the following is an analog technique that can be applied when the bandwidth of a link
(in hertz) is greater than the combined bandwidths of the signals to be transmitted?
A) FDM
B) TDM
C) CDM
D) WDM
1.6 Which of the following was designed as an alternative to the T-1 line (1.544 Mbps)?
A) ADSL lite
B) HDSL
C) DSL
D) VDSL
1.7 Mapping from MAC address to IP address is done by ________.
A) SNMP
B) ARP
C) SMTP
D) RARP
1.8 To deliver a message to the correct application program running on a host, which of the
following address must be consulted?
A) internet protocol
B) physical
C) port
D) memory
1.9 A multistage switch with micro switches at each stage that route the packets based on the
output port represented as a binary string is ________.
A) a Space-Division switch
B) a Crossbar switch
C) a Router
D) a Banyan switch
1.10 Which of the following signal can be used for short-range communication in a closed area using
line-of-sight propagation?
A) Infrared
B) Bluetooth
C) Radio
D) Microwave

2. Each statement below is either TRUE or FALSE. Choose the most appropriate one and ENTER in the “tear-off” sheet attached to the question paper, following instructions therein. (1x10)

2.1 The physical layer in the traditional telephone network uses the packet-switching approach.
2.2 Synchronous Data Link Control (SDLC) protocol has more control overhead than Asynchronous
Data Link Control (ADLC) protocol.
2.3 ADSL is a symmetric communication technology designed for residential users; it is not suitable
for businesses.
2.4 Forward error correction is the process in which the receiver tries to guess the message by
using redundant bits.
2.5 In IEEE 802.11b LAN, wireless technology is used.
2.6 IP is a best effort connectionless protocol.
2.7 A bridge can use the spanning tree algorithm to create a loopless topology.
2.8 Gigabit Ethernet access methods include half-duplex mode using traditional CSMA/CD (not
common) and full-duplex mode (most popular method).
2.9 There are three types of addresses in IPv6: unicast, anycast, and multicast.
2.10 Mail services are available to network users through the application layer.

3. Match words and phrases in column X with the closest related meaning/word(s)/phrase(s) in column Y. Enter your selection in the “tear-off” answer sheet attached to the question paper, following instructions therein. (1x10)
X
Y
3.1
Although coaxial cable has a much higher bandwidth, the signal weakens rapidly and requires the frequent use of
A.
query messages
3.2
Flow control refers to a set of procedures used to restrict the amount of data that the sender can send before waiting for
B.
cryptography
3.3
HDLC handle data transparency by adding a 0 whenever there are five consecutive 1s following a 0. This is called
C.
redundancy
3.4
Converting plain text to cipher text and vice-versa
D.
Sampling
3.5
The first step in digitizing an analog signal
E.
Network
3.6
The SIP is an application protocol that establishes, manages, and terminates
F.
bit stuffing
3.7
Secure wireless multiplexing
G.
a noisy channel
3.8
The Shannon capacity determines the theoretical maximum data rate for
H.
CDMA
3.9
The central concept in detecting or correcting errors is
I.
bridge
3.10
ICMP messages are divided into two broad categories: error- reporting messages and
J.
repeaters


K.
error correction


L.
a multimedia session


M.
acknowledgment

4. Each statement below has a blank space to fit one of the word(s) or phrase(s) in the list
below. Enter your choice in the “tear-off” answer sheet attached to the question paper, following instructions therein. (1x10)

A.
broadcast
B.
telnet
C.
IP address
D.
UDP
E.
block coding
F.
the teardown phase
G.
RARP
H.
VPN
I.
HTTP
J.
Aloha
K.
resistance
L.
The class
M.
segmentation





4.1 To implement ________ over the Internet, tunneling is used.
4.2 VLANs create ________ domains.
4.3 ________ of an IP address is easily determined by examination of the first byte.
4.4 The main advantage of PCM system is its ________ to system noise offered by digital signals.
4.5 In circuit switching, the resources need to be reserved during the setup phase; the resources
remain dedicated for the entire duration of data transfer until ________.
4.6 In ________, the message is divided into blocks, each of k bits, called datawords.
4.7 The protocol used to transfer HTML pages is called ________.
4.8 In remote login, ________ is used to access distant servers.
4.9 In the Internet, ________ is used to forward data packets in intermediate routers.
4.10 ________ works on transport layer of OSI reference model.

PART TWO
(Answer any FOUR questions)
5.
a) What are the advantages and disadvantages of using a twisted pair? What are its two forms?
b) Explain in short the ‘OSI Model’. List at least four functions performed by network layer.
c) Explain the term modulation. How is it different from encoding? Why is frequency modulation
superior to amplitude modulation?
(5+5+5)
6.
a) What is VLAN? Discuss how VLAN enables logical topologies on top of the physical network
infrastructure.
b) Compare virtual circuit with datagram subnet.
c) What is a subnet mask and why is it required?
(5+5+5)
7.
a) Explain briefly the roles of repeaters, bridges, routers and gateways in internetworking. Also
mention the layers on which they function.
b) When is an ARP request packet generated? Describe the various steps that take place when a
host receives an ARP request packet.
c) Discuss the advantages and disadvantages of packet switching over circuit switching.
(5+5+5)
8.
a) What is a network firewall? How are they different from application firewall?
b) Explain frequency reuse principal. What is handoff in wireless communication?
c) How does a peer-to-peer network differ from client/server network?
(5+5+5)
9.
a) The next-generation IP, or IPv6, has some advantages over IPv4. Write down the advantages of
IPv6 over IPv4.
b) Explain with the help of an example the difference between Bellman-Ford algorithm and
Dijkstra's algorithm for routing.
c) List and briefly define the key elements of SNMP.
(5+5+5)