PART A
COMPUTER NETWORK MCQ
UNIT 1
ISO stands for
International Organization for Standardization
The main principle of layered architecture is
Separation of responsibility
In layered architecture, each layer is responsible for a
finite
The convention and rules used in such communications are collectively known as
Layer protocol
OSI has two meanings refers to
Both a & b
Network is the term used for a group of
both a and b
Transmission media deals with the types of medium used , which is dictated by the
All of these
In error control, this corruption could be in the form of
Both a & b
Protocols should provide at least logical channels per connection
2
Data exchange can take place between any workstations
3
Depending on the nature of the involved application in layered architecture, the dialog type may be
All of these
Some good examples of presentation problems are the existing incompatibilities between the
Both a & b
This is the entities in the same layers but on different computers
Peer entities
Which function of the layer provides certain services
Service provider
Which function of the layer uses certain services
service user
Which is the point from where services can be accessed .each point is the unique addres
SAP
Which is the reliable connectionless service with acknowledgement
Registered E-mail
Which is the unreliable connectionless service without acknowledgement
Junk E-mail
Which service is specified by a set of primitives available to a service user to interact with the serviceprovider
Both a & b
Which are parameters to define conditions
Primitives
The OSI interface is a process of communication between adjacent layers in which data is passed between
All of these
The functions of the physical layer are
All of these
Some of the examples of MAC are
Both a & b
Some examples of APIs are
All of these
Which is the user interface to the mail system
User agent
There are a number of e-mail packages available. Some of them are free like
All of these
SMTP uses
tcp
The SMTP server also allows
Telnet service
The information exchanged between two computers is physically carried by means of
Electrical signal
For two computers to reliably exchange data, they must have a
Both a & b
UNIT 2
Which of the following tasks is not done by data link layer?
d) channel coding
Which sublayer of the data link layer performs data link functions that depend upon the type of medium?
b) media access control sublayer
Automatic repeat request error management mechanism is provided by ________
a) logical link control sublayer
When 2 or more bits in a data unit has been changed during the transmission, the error is called ____________
burst error
CRC stands for __________
a) cyclic redundancy check
Which of the following is a data link protocol?
d)all of these
Which of the following is the multiple access protocol for channel access control?
b) Both CSMA/CD & CSMA/CA
The technique of temporarily delaying outgoing acknowledgements so that they can be hooked onto the next outgoing data frame is called ____________
a) piggybacking
Which of the following would be found in a Data Link layer header?
The source’s physical address
What is a primary function of the trailer information added by the data link layer encapsulation?
Supports error detection
Error detection at the data link layer is achieved by?
Cyclic redundancy codes
Under mark parity,each parity bit is?
Always set to 1
Which of the following devices is a PC component that connects the computer to the network?
NIC (Network Interface Card)
Switch is a Device of _________ Layer of OSI Model.
Data Link Layer
HUB is a _________ Device and Switch is a ________ Device.
Broadcast, Unicast
The data link layer takes the packets from _____ and encapsulates them into frames for transmission.
network layer
Which one of the following task is done by data link layer?
framing
In the _________Protocol, if no acknowledgment for a frame has arrived, we resend all outstanding frames.
Go-Back-N ARQ
In the _________ protocol we avoid unnecessary transmission by sending only frames that are corrupted.
Selective-Repeat ARQ
Both Go-Back-N and Selective-Repeat Protocols use a _________.
sliding window
In Go-Back-N ARQ, if 5 is the number of bits for the sequence number, then the maximum size of the send window must be _____.
31
In Go-Back-N ARQ, if 5 is the number of bits for the sequence number, then the maximum size of the receive window must be _____.
1
In Selective Repeat ARQ, if 5 is the number of bits for the sequence number, then the maximum size of the send window must be _____.
16
High-level Data Link Control (HDLC) is a _______ protocol for communication over point-to-point and multipoint links.
bit-oriented
The most common protocol for point-to-point access is the Point-to-Point Protocol (PPP), which is a _________protocol.
byte-oriented
_______ control refers to a set of procedures used to restrict the amount of data that the sender can send before waiting for acknowledgment.
Flow
_________control in the data link layer is based on automatic repeat request, which is the retransmission of data.
Error
In Stop-and-Wait ARQ, we use sequence numbers to number the frames. The sequence numbers are based on __________arithmetic.
modulo-4
In Stop-and-Wait ARQ, the acknowledgment number always announces in ______ arithmetic the sequence number of the next frame expected.
modulo-2
In the Go-Back-N Protocol, if the size of the sequence number field is 8, the sequence numbers are in ________ arithmetic.
modulo-256
Unit 3
Which one of the following is not a function of network layer?
c) error control
The network layer protocol for internet is __________
b) internet protocol
ICMP is primarily used for __________
a) error and diagnostic functions
Which of the following is not applicable for IP?
a) Error reporting
Which field helps to check rearrangement of the fragments?
a) offset
The size of an IP address in IPv6 is _________
b) 128 bits
IPv6 does not use _________ type of address.
broadcast
The source-quench message in ICMP was designed to add a kind of ____________ to the IP.
b) flow control
The term that is used to place packet in its route to its destination is called __________
Forwarding
Next-Hop Method is used to reduce contents of a _________
Routing Table
In Unicast Routing, Dijkstra algorithm creates a shortest path tree from a ________
Graph
Which protocol gives a full route table update every 30 seconds?
RIP
An area is _______.
part of an AS
To create a neighborhood relationship, a router running BGP sends an ________ message.
Open
The telephone line is an example of
Point-to-point link
In path vector routing, the Internet is divided into hierarchical domains called
Autonomous networks
IGMP operates __________.
locally
Which of the following routing algorithms can be used for network layer design?
all of the mentioned
Which one of the following algorithm is not used for congestion control?
routing information protocol
The _________ field determines the lifetime of IPv6 datagram
Hop limit
Which among the following features is present in IPv6 but not in IPv4?
Anycast address
Internet Control Message Protocol (ICMP) has been designed to compensate _________
All of the mentioned
Which of these is not a type of error-reporting message?
Router error
In Multicast Routing Protocol, flooding is used to broadcast packets but it creates ________
b) Loops
Which command displays RIP routing updates?
Debug IP rip
_________ is the default administrative distance of RIP.
120
The computation of the shortest path in OSPF is usually done by ____________
Dijkstra’s algorithm
In ________ routing, we assume that there is one node (or more) in each autonomous system that acts on behalf of the entire autonomous system.
path vector
___________ is an interdomain routing protocol using path vector routing.
BGP
In _______, the router may forward the received packet through several of its interfaces.
b. multicasting
UNIT 4
Which of the following are transport layer protocols used in networking?
TCP and UDP
An endpoint of an inter-process communication flow across a computer network is called __________
socket
Which one of the following is a version of UDP with congestion control?
datagram congestion control protocol
Transport layer protocols deals with ____________
process to process communication
Which of the following is a transport layer protocol?
stream control transmission protocol
Which of the following is false with respect to TCP?
Unreliable
In TCP, sending and receiving data is done as _______
Stream of bytes
In segment header, sequence number and acknowledgement number fields refer to _______
Byte number
Size of TCP segment header ranges between ___________
20 and 60 bytes
Return value of the UDP port “Chargen” is _______
String of characters
Beyond IP, UDP provides additional services such as _______
Demultiplexing and error checking
What is the main advantage of UDP?
Low overhead
Port number used by Network Time Protocol (NTP) with UDP is ________
123
What is the header size of a UDP packet?
8 bytes
“Total length” field in UDP packet header is the length of _________
UDP header plus data
In an SCTP packet, control chunks come ___________ data chunks.
before
The server program tells its TCP that it is ready to accept a connection. This process is called ___________
Passive open
SYNC flooding attack belongs to a type of security attack known as ___________
Denial-of-service attack
A client that wishes to connect to an open server tells its TCP that it needs to be connected to that particular server. The process is called ___________
Active open
Stream control transmission protocol is a new
message oriented transport layer protocol
SCTP protocol combines the best features of
Both a and c
The combination of IP address and port number is called
socket address
The value of window size determined by
the receiver
In SCTP, the acknowledgment number and window size are part of each ________.
control chunk
A connection in SCTP is called an ____________.
association
The association identifier in SCTP is __________________.
a unique verification tag
In SCTP, a data chunk is numbered using ________.
a TSN
UDP needs the _______ address to deliver the user datagram to the correct application process.
port
Transmission control protocol ___________
all of the mentioned
Socket-style API for windows is called ____________
b) winsock
UNIT 5
Which is not a application layer protocol?
TCP
The packet of information at the application layer is called __________
Message
Application layer offers _______ service.
End to end
Pick the odd one out.
Interactive games
Which of the following is an application layer service?
All of the mentioned
Electronic mail uses which Application layer protocol?
SMTP
Application layer protocol defines ____________
all of the mentioned
Which one of the following protocol delivers/stores mail to reciever server?
simple mail transfer protocol
Which one of the following is not an application layer protocol?
resource reservation protocol
When displaying a web page, the application layer uses the _____________
HTTP protocol
The values GET, POST, HEAD etc are specified in ____________ of HTTP message
Request line
What is a web browser?
all of the mentioned
Common gateway interface is used to _______
generate executable files from web content by web server
Which one of the following allows client to update their DNS entry as their IP address change?
dynamic DNS
In Network Management System, the division that is responsible for controlling access to network based on a predefined policy is called _________
Security Management
Full duplex mode increases the capacity of each domain by ________
10 to 20 mbps
_______ allows you to connect and login to a remote computer
Telnet
Telnet is used for _______
Remote Login
All telnet operations are sent as ________
8 bits
FTP uses _________ parallel TCP connections to transfer a file.
2
FTP server _____________
Maintains state information
The commands, from client to server, and replies, from server to client, are sent across the control connection in ________ bit ASCII format.
7
The data transfer mode of FTP, in which all the fragmenting has to be done by TCP is ________
Stream mode
The password is sent to the server using ________ command
PASS
Secure shell (SSH) network protocol is used for __________
all of the mentioned
Which one of the following authentication method is used by SSH?
password
An email client needs to know the _________ of its initial SMTP server.
IP address
SMTP defines _______
message transport
Which one of the following is an architecture paradigms?
Both Peer-to-Peer & Client-Server
Application developer has permission to decide the following on transport layer side
Both Transport layer protocol and Maximum buffer size
PART B
CN PART B
UNIT 1
A confirmed services is defined with a
All of these
Examples of data link layers are
Both a & b
The data link layer also deals with the issue of addressing what is popularly known as
All of these
The routing of network layer may be
None of these
Which protocol uses the transport layer
TCP/IP
The data link layer is also known as
Link layer
TCP/IP layer specifies the
Physical layer
The Packet format and protocol at internet layer is called
Internet protocol
Which protocols are found in a Internet Layer of TCP/IP model
All of these
E-mail has two parts namely
Both a & b
MTA stands for
Message Transfer Agent
E-mail address has three parts
All of these
Data communication system within a building or campus is________
LAN
Application layer is implemented in ____________
End system
Which transmission media provides the highest transmission speed in a network?
optical fiber
The fiber optics transmission runs at ------------
1000
Physical layer accepts data or information from the data link layer and converts it into hardware specific operations so as to transfer the message through---------------------
physical cables
SMTP is the
de facto
MIME stands for
Multipurpose Internet Mail Extensions
POP3 stands for
Post Office Protocol
UNIT 2
In _________, the station configuration is unbalanced. We have one primary station and multiple secondary stations.
NRM
In _________, the configuration is balanced. The link is point-to-point, and each station can function as a primary and a secondary.
ABM
In PPP, the ________ is responsible for establishing, maintaining, configuring, and terminating links.
LCP
In PPP, ________ is a simple authentication procedure with a two-step process.
PAP
In PPP, _______ is a three-way hand-shaking authentication protocol in which the password is kept secret; it is never sent online.
CHAP
_______ is a standard developed by ANSI for fiber-optic networks
SONET
_______ is a standard developed by ITU-T.
SDH
SONET has defined a hierarchy of signals called ________.
STSs
SDH has defined a hierarchy of signals called ________.
STMs
Station A uses 32 byte packets to transmit messages to Station B using a sliding window protocol. The round trip delay between A and B is 80 milliseconds and the bottleneck bandwidth on the path between A and B is 128 kbps. What is the optimal window size that A should use?
40
A bit-stuffing based framing protocol uses an 8-bit delimiter pattern of 01111110. If the output bit-string after stuffing is 01111100101, then the input bit-string is
111110101
Consider a selective repeat sliding window protocol that uses a frame size of 1 KB to send data on a 1.5 Mbps link with a one-way latency of 50 msec. To achieve a link utilization of 60%, the minimum number of bits required to represent the sequence number field is ________.
5
The message 11001001 is to be transmitted using the CRC polynomial x^3 + 1 to protect it from errors. The message that should be transmitted is:
11001001011
In a token ring network the transmission speed is 10^7 bps and the propagation speed is 200 metres/micro second. The 1-bit delay in this network is equivalent to:
20 metres of cable
There are n stations in a slotted LAN. Each station attempts to transmit with a probability p in each time slot. What is the probability that ONLY one station transmits in a given time slot?
np(1-p)^(n-1)
In Ethernet when Manchester encoding is used, the bit rate is:
none of these
Consider the data of previous question. Suppose that the sliding window protocol is used with the sender window size of 2^i where is the number of bits identified in the previous question and acknowledgments are always piggybacked. After sending 2^i frames, what is the minimum time the sender will have to wait before starting transmission of the next frame? (Identify the closest choice ignoring the frame processing time.)
20ms
Frames of 1000 bits are sent over a 10^6 bps duplex link between two hosts. The propagation time is 25ms. Frames are to be transmitted into this link to maximally pack them in transit (within the link). What is the minimum number of bits (i) that will be required to represent the sequence numbers distinctly? Assume that no time gap needs to be given between transmission of two frames.
5
Let G(x) be the generator polynomial used for CRC checking. What is the condition that should be satisfied by G(x) to detect odd number of bits in error?
1+x is a factor of G(x)
Determine the maximum length of the cable (in km) for transmitting data at a rate of 500 Mbps in an Ethernet LAN with frames of size 10,000 bits. Assume the signal speed in the cable to be 2,00,000 km/s
2
UNIT 3
Multicast link state routing uses the _______ tree approach.
a. source-based
MOSPF is a _______ protocol.
a. data-driven
PIM-DM is used in a _______ multicast environment, such as a LAN.
d. none of the above
In distance vector routing algorithm, the routing tables are updated .....................
a. by exchanging information with the neighbours
To do multicast routing, each router computes a .....................
b. Spanning tree
A normal Flooding technique is an example of ..................
d. Broadcasting
When a host knows its physical address but not its IP address, it can use _____.
c. RARP
In an IPv4 packet, the value of HLEN is
b.5
In IPv4, formula for Length of data =
b. Total length – header length
A 4 byte IP address consists of __________
c) network address & host address
The TTL field has value 10. How many routers (max) can process this datagram?
c) 10
During debugging, we can use the ____________ program to find if a host is alive and responding.
c) ping
In windows ____________ can be used to trace the route of the packet from the source to the destination.
b) tracert
"What is the correct order of the operations of OSPF?i – Hello packets
ii – Propagation of link-state information and building of routing tables
iii – Establishing adjacencies and synchronization of database
" b) i-iii-ii
In OSPF database descriptor packet, which field is used to detect a missing packet? c) Database descriptor sequence number
What is the IP protocol number for OSPF packets?
a) 89
A _______ message tells an upstream router to stop sending multicast messages for a specific group through a specific router.
c. prune
The idea of aggregation is equal to
b. Subnetting
An IGMP query is sent from a _______ to a _______.
d. router; host or router
How can you see the address of the DHCP server from which a client received its IP address? c. By using IPCONFIG/ALL
UNIT 4
TCP process may not write and read data at the same speed. So we need __________ for storage.
b) Buffers
TCP groups a number of bytes together into a packet called _______
c) Segment
Communication offered by TCP is ________
a) Full-duplex
The value of acknowledgement field in a segment defines _______
b) sequence number of the next byte to be received
The receiver of the data controls the amount of data that are to be sent by the sender is referred to as ___________
a) Flow control
What allows TCP to detect lost segments and in turn recover from that loss?
b) Acknowledgment number
Which of the following is false with respect to UDP?
a) Connection-oriented
Which is the correct expression for the length of UDP datagram?
a) UDP length = IP length – IP header’s length
The ______ field is used to detect errors over the entire user datagram.
b) checksum
In Three-Way Handshaking process, the situation where both the TCP’s issue an active open is ___________
c) Simultaneous open
Flow control in SCTP is similar to that in
a)TCP
SCTP,association allows multiple IP address for
b)each end
The FIN+ACK segment consumes--------------sequence number if it does not carry data
c)one
SCTP allows __________ service in each association.
B) multistream
SCTP association allows _____________ for each end.
B) multiple IP addresses
There is no need for a header length field in SCTP because ________________.
C) both a and b
User datagram protocol is called connectionless because _____________
a) all UDP packets are treated independently by transport layer
A _____ is a TCP name for a transport service access point.
a) port
To achieve reliable transport in TCP, ___________ is used to check the safe and sound arrival of data.
d) Acknowledgment
Suppose a TCP connection is transferring a file of 1000 bytes. The first byte is numbered 10001. What is the sequence number of the segment if all data is sent in only one segment? b) 10001
TCP allows the sending process to deliver data as a _______of bytes and allows the receiving process to obtain data as a _________ of bytes.
B) stream; stream
The ports ranging from 49,152 to 65,535 can be used as temporary or private port numbers. They are called the ________ ports.
C) dynamic
The inclusion of the checksum in the TCP segment is ________.
B) mandatory
__________ control regulates the amount of data a source can send before receiving an acknowledgment from the destination.
B) Flow
UNIT 5
E-mail is _________
d) Elastic application
To deliver a message to the correct application program running on a host, the _______ address must be consulted.
c) Port
Which is a time-sensitive service?
e) Internet telephony
Transport services available to applications in one or another form _________
c) All of the mentioned
The ____________ translates internet domain and host names to IP address.
a) domain name system
Which one of the following is an internet standard protocol for managing devices on IP network?
b) simple network management protocol
Which one of the following is not correct?
c) All of the mentioned
The HTTP request message is sent in _________ part of three-way handshake.
d) Third
A DNS client is called _________
b) DNS resolver
If a server has no clue about where to find the address for a hostname then _______
a) server asks to the root server
The application-level protocol in which a few manager stations control a set of agents is called ______
c) SNMP
SNMP is the framework for managing devices in an internet using the ______
a) TCP/IP protocol
Configuration management can be divided into which two subsystems?
a) Reconfiguration and documentation
Which operating mode of telnet is full duplex?
b) line mode
AbsoluteTelnet is a telnet client for _______ Operating system.
a) windows
If 5 files are transferred from server A to client B in the same session. The number of TCP connections between A and B is _______
c) 6
SSH can be used in only _____________
d) both unix-like and windows systems
SMTP is not used to deliver messages to ______
b) user’s word processor
Which one of the following allows a user at one site to establish a connection to another site and then pass keystrokes from local host to remote host?
c) Telnet
The ASCII encoding of binary data is called
a) base 64 encoding
Which protocol is a signaling communication protocol used for controlling multimedia communication sessions?
a) session initiation protocol
The default connection type used by HTTP is _________
a) Persistent
The time taken by a packet to travel from client to server and then back to the client is called __________
b) RTT
A piece of icon or image on a web page associated with another webpage is called ______ b) hyperlink
Which one of the following is not used to generate dynamic web pages?
c) CSS
The entire hostname has a maximum of ___________
a) 255 characters
The domain name system is maintained by _______
a) distributed database system
FTP is built on _____ architecture.
a) Client-server
SSH uses ___________ to authenticate the remote computer.
a) public-key cryptography
SSH-2 does not contain ______________
b) user authentication layer
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