Computer Science and Information Technology - Computer Network
Exam Duration: 45 Mins Total Questions : 30
Which of these network devices belongs at the OSI physical layer?
- (a)
Repeater
- (b)
Router
- (c)
Switch
- (d)
Bridge
Which of the following layer is responsible for routing packets?
- (a)
Transport layer
- (b)
Network layer
- (c)
Data link
- (d)
Physical
Which of the following error detection methods uses ones complement arithmetic?
- (a)
Aimple parity check
- (b)
Hamming code
- (c)
CRC
- (d)
checksum
In go-back-n the window size of receiver side is always
- (a)
2
- (b)
1
- (c)
2n
- (d)
2n-1
If L is the length of the frame, B is the band width and R is the propagation delay then what condition holds good to have at least 50%,
efficiency in stop-and-wait protocol?
- (a)
L=BR
- (b)
L < BR
- (c)
L=2BR
- (d)
L \(\ge\) BR
A routing table contains
- (a)
The destination network IP
- (b)
The hop count
- (c)
next hop router IP
- (d)
All of the above
Which of the following is not provided in digital signature?
- (a)
Encryption key
- (b)
Decryption key
- (c)
Both (a) and (b)
- (d)
It is kept secret that which one is public
Which of the following is not a field in the ethernet message packet ?
- (a)
Type
- (b)
Data
- (c)
Pin code
- (d)
Address
In a broad sense, a railway track is an example of
- (a)
simplex
- (b)
half duplex
- (c)
full duplex
- (d)
All of these
FDDI is
- (a)
ring network
- (b)
star network
- (c)
mesh network
- (d)
bus based network
ICMP ( Internet Control Message Protocol ) is
- (a)
a protocol used to dynamically bind a high level IP address to low level physical hardware address
- (b)
a protocol for transferring files from one machine to anther
- (c)
a protocol used to monitor computers
- (d)
a protocol that handles error and control messages
Working of the WAN generally involves
- (a)
satellite
- (b)
frame Delay
- (c)
ATM
- (d)
All of these
The X.25 standard specifies a
- (a)
technique for dial access
- (b)
technique for start stop data
- (c)
data bit rare
- (d)
DTE/DCE interface
The frame relay committed information rate represents
- (a)
maximum data rate on the network
- (b)
steady state data rate on the network
- (c)
minimum data rate on the network
- (d)
interface data rate.
Slotted ALOHA
- (a)
divides time into discrete intervals
- (b)
requires global time synchronization
- (c)
Both (a) and (b)
- (d)
None of the above
In networking terminology UTP means
- (a)
unshielded twisted pair
- (b)
uniquitous teflon port
- (c)
uniformly terminating port
- (d)
unshielded T-connector port
Which one of the following is not a class of LAN ?
- (a)
Broad band
- (b)
CSMA/CD
- (c)
Token bus
- (d)
Token ring
Which of the following TCP/IP internet protocol a diskless machine uses to obtain its IP address from a server ?
- (a)
RDP
- (b)
RARP
- (c)
RIP
- (d)
X.25
At which layer of the OSI model the router configuration problem resides ?
- (a)
Transport
- (b)
Network
- (c)
Logical Link
- (d)
Physical
In the carrier sense network if the prevailing condition is a channel busy and if the technique used is
- (a)
non-persistent then it results in randomised wait and sense
- (b)
1-persistent then the channel is continually sensed
- (c)
p-persistent then randomised retransmission is done
- (d)
Both (a) and (b)
Which one is least expensive that can support 100 byte/s ?
- (a)
Coaxial
- (b)
UTP
- (c)
Fiber optic
- (d)
STP
At network layer protocol defined by TCP/IP is
- (a)
TCP
- (b)
UDP
- (c)
IP
- (d)
None of these
Which of the following is not an advantage of synchronous transmission over asynchronous transmission ?
- (a)
Can be used effectively for high volumes of data
- (b)
High level of error detection can be incorporated
- (c)
Each byte is protected by a separate parity bit
- (d)
Self clocking facility of encoding systems can be effectively used.
You need to determine whether the configuration is initialized or a duplicate IP address is configured oon your NT workstation. Which utility should you use ?
- (a)
arp.exe
- (b)
ipconfig.exe
- (c)
ping.exe
- (d)
nutstat.exe
The store and forward machanism is used in
- (a)
packet switching
- (b)
message switvhing
- (c)
circuit switching
- (d)
data gram switvhing
A go-back-n ARQ uses a window of size 15. How many bits are needed to define the sequence number ?
- (a)
15
- (b)
4
- (c)
16
- (d)
5
Which of the following IP addresses is valid to be assigned to a host ?
- (a)
127.0.0.1
- (b)
192.248.16.255
- (c)
25.2.25.55
- (d)
150.7.0.0
IP address : 124.133.112.66
Mark : 255.255.224.0
The subnet address is
- (a)
124.133.0.0
- (b)
124.133.96.0
- (c)
225.225.0.0
- (d)
124.133.122.0
IP address : 124.133.112.66
Mark : 255.255.224.0
What is the maximum number of subnets in class C using the mark 255.255.255.240 ?
- (a)
16
- (b)
8
- (c)
5
- (d)
4
Two station A and B are connected via a point-to-point link and exchange frames both employing the go-back-n sliding window protocol with window size 7. Sequence number is of 3 bits.
Station A sends frames 0 through 6. Station B receives them in order. Station B sends 1 data frame to A (which A receives currently) after receiving 4 but before receiving frame 5. What will be the buffer frames in the current window of A ?
- (a)
4, 5, 6, 7, 0, 1, 2
- (b)
6, 7, 0, 1, 2, 3, 4
- (c)
5, 6, 7, 0, 1, 2, 3
- (d)
3, 4, 5, 6, 7, 0, 1