Computer Networks MCQ Set 1
1. Which of this is not a constituent of residential telephone line?
a) A high-speed downstream channel
b) A medium-speed downstream channel
c) A low-speed downstream channel
d) None of the mentioned
Answer
Answer: c [Reason:] The third part is ordinary two way telephone channel.
2. In DSL telco provides these services
a) Wired phone access
b) ISP
c) All of the mentioned
d) None of the mentioned
Answer
Answer: c [Reason:] The same company which provides phone connection is also its ISP in DSL.
3. The function of DSLAM is
a) Convert analog signals into digital signals
b) Convert digital signals into analog signals
c) Amplify digital signals
d) None of the mentioned
Answer
Answer: a [Reason:] The DSLAM located in telco’s Central Office does this function.
4. The following term is not associted with DSL
a) DSLAM
b) CO
c) Splitter
d) CMTS
Answer
Answer: d [Reason:] Cable modem termination system is used in cable internet access.
5. HFC contains
a) Fibre cable
b) Coaxial cable
c) Both of the mentioned
d) None of the mentioned
Answer
Answer: c [Reason:] None.
6. Choose the statement which is not applicable for cable internet access
a) It is a shared broadcast medium
b) It includes HFCs
c) Cable modem connects home PC to Ethernet port
d) Analog signal is converted to digital signal in DSLAM
Answer
Answer: d [Reason:] In cable access analog signal is converted to digital signal by CMTS.
7. Among the optical-distribution architectures that is essentially switched ehternet is
a) AON
b) PON
c) NON
d) None of the mentioned
Answer
Answer:a [Reason:] Active optical networks are essentially switched ehternets.
8. StarBand provides
a) FTTH internet access
b) Cable access
c) Telephone access
d) Satellite access
Answer
Answer: d [Reason:] None.
9. Home Access is provided by
a) DSL
b) FTTP
c) Cable
d) All of the mentioned
Answer
Answer: d [Reason:] None.
10. ONT is connected to splitter using
a) High speed fibre cable
b) HFC
c) Optical cable
d) None of the mentioned
Answer
Answer: c [Reason:] None.
11. These factors affect transmission rate in DSL
a) The gauge of the twisted-pair line
b) Degree of electrical interfernece
c) Shadow fading
d) Both a and b
Answer
Answer: d [Reason:] Because DSL is made of twisted wire copper pair.
Computer Networks MCQ Set 2
1. The IETF standards documents are called
a) RFC
b) RCF
c) ID
d) None of the mentioned
Answer
Answer: a [Reason:] Request For Comments.
2. In the layer hierarchy as the data packet moves from the upper to the lower layers, headers are
a) Added
b) Removed
c) Rearranged
d) Modified
Answer
Answer: a [Reason:] Every layer adds its own header to the packet from previous layer.
3. The structure or format of data is called
a) Syntax
b) Semantics
c) Struct
d) None of the mentioned
Answer
Answer: a [Reason:] Semantics defines how a particular pattern to be interpreted, and what action is to be taken based on that interpretation.
4. Communication between a computer and a keyboard involves ______________ transmission
a) Automatic
b) Half-duplex
c) Full-duplex
d) Simplex
Answer
Answer: d [Reason:] Data flows in single direction.
5. The first Network
a) CNNET
b) NSFNET
c) ASAPNET
d) ARPANET
Answer
Answer: d [Reason:] None.
6. The _______ is the physical path over which a message travels
a) Path
b) Medium
c) Protocol
d) Route
Answer
Answer: b [Reason:] Message travel from sender to reciever via a medium using a protocol.
7. Which organization has authority over interstate and international commerce in the communications field?
a) ITU-T
b) IEEE
c) FCC
d) ISOC
Answer
Answer: c [Reason:] None.
8. Which of this is not a network edge device?
a) PC
b) Smartphones
c) Servers
d) Switch
Answer
Answer: d [Reason:] Network egde devices refer to host systems, which can host applications like web browser.
9. A set of rules that governs data communication
a) Protocols
b) Standards
c) RFCs
d) None of the mentioned
Answer
Answer: a [Reason:] None.
10. Three or more devices share a link in ________ connection
a) Unipoint
b) Multipoint
c) Point to point
d) None of the mentioned
Answer
Answer: b [Reason:] None.
Computer Networks MCQ Set 3
1. Which of the following delay is faced by the packet in travelling from one end system to another ?
a) Propagation delay
b) Queuing delay
c) Transmission delay
d) All of the mentioned
Answer
Answer: d [Reason:] None.
2. For a 10Mbps Ethernet link, if the length of the packet is 32bits, the transmission delay is(in milliseconds)
a) 3.2
b) 32
c) 0.32
d) None of the mentioned
Answer
Answer: a [Reason:] Transmission rate = length / transmission rate = 32/10 = 3.2milli seconds.
3. The time required to examine the packet’s header and determine where to direct the packet is part of
a) Processing delay
b) Queuing delay
c) Transmission delay
d) All of the mentioned
Answer
Answer: a [Reason:] None.
4. Traffic intensity is given by, where L = number of bits in the packet a = average rate R = transmission rate
a) La/R
b) LR/a
c) R/La
d) None of the mentioned
Answer
Answer: a [Reason:] None.
5. In the transfer of file between server and client, if the transmission rates along the path is 10Mbps, 20Mbps, 30Mbps, 40Mbps. The throughput is usually
a) 20Mbps
b) 10Mbps
c) 40Mbps
d) 50Mbps
Answer
Answer: b [Reason:] The throughput is generally the transmission rate of bottleneck link.
6. If end to end delay is given by dend-end = N(dproc + dtrans + dprop) is a non congested network. The number of routers between source and destination is
a) N/2
b) N
c) N-1
d) 2N
Answer
Answer: c [Reason:] None.
7. The total nodal delay is given by
a) dnodal = dproc – dqueue + dtrans + dprop
b) dnodal = dproc + dtrans – dqueue
c) dnodal = dproc + dqueue + dtrans + dprop
d) dnodal = dproc + dqueue – dtrans – dprop
Answer
Answer: c [Reason:] None.
8. In a network, If P is the only packet being transmitted and there was no earlier transmission, which of the following delays could be zero
a) Propogation delay
b) Queuing delay
c) Transmission delay
d) Processing delay
Answer
Answer: b [Reason:] None.
9. Transmission delay does not depend on
a) Packet length
b) Distance between the routers
c) Transmission rate
d) None of the mentioned
Answer
Answer: b [Reason:] Transmission delay = packet length / transmission rate
10. Propagation delay depends on
a) Packet length
b) Transmission rate
c) Distance between the routers
d) None of the mentioned
Answer
Answer: c [Reason:] Propagation delay is the time it takes a bit to propagate from one router to the next.
Computer Networks MCQ Set 4
1. Expansion of FTP is
a) Fine Transfer Protocol
b) File Transfer Protocol
c) First Transfer Protocol
d) None of the mentioned
Answer
Answer: b [Reason:] None.
2. FTP is built on _____ architecture
a) Client-server
b) P2P
c) Both of the mentioned
d) None of the mentioned
Answer
Answer: a [Reason:] None.
3. FTP uses _________ parallel TCP connections to transfer a file
a) 1
b) 2
c) 3
d) 4
Answer
Answer: b [Reason:] Control connection and data connection.
4. Identify the incorrect statement
a) FTP stands for File Transfer Protocol
b) FTP uses two parallel TCP connections
c) FTP sends its control information in-band
d) FTP sends exactly one file over the data connection
Answer
Answer: c [Reason:] FTP is out-of-band as it has separate control connection.
5. If 5 files are transfered from server A to client B in the same session. The number of TCP connection between A and B is
a) 5
b) 10
c) 2
d) 6
Answer
Answer: d [Reason:] 1 control connection and other 5 for five file transfers.
6. FTP server
a) Mantains state
b) Is stateless
c) Has single TCP connection for a file transfer
d) None of the mentioned
Answer
Answer: a [Reason:] None.
7. The commands, from client to server, and replies, from server to client, are sent across the control connection in ________ bit ASCII format
a) 8
b) 7
c) 3
d) 5
Answer
Answer: b [Reason:] None.
8. Find the FTP reply whose message is wrongly matched
a) 331 – Username OK, password required
b) 425 – Can’t open data connection
c) 452 – Error writing file
d) 452 – Can’t open data connection
Answer
Answer: d [Reason:] None.
9. Mode of data transfer in FTP, where all the is left to TCP
a) Stream mode
b) Block mode
c) Compressed mode
d) None of the mentioned
Answer
Answer: a [Reason:] None.
10. The password is sent to the server using ________ command
a) PASSWD
b) PASS
c) PASSWORD
d) None of the mentioned
Answer
Answer: b [Reason:] None.
Computer Networks MCQ Set 5
1. Which of the following is not applicable for IP?
a) Error reporting
b) Handle addressing conventions
c) Datagram format
d) Packet handling conventions
Answer
Answer: a [Reason:] Error reporting is handled by ICMP.
2. Which of the following field in IPv4 datagram is not related to fragmentation?
a) Flags
b) Offset
c) TOS
d) Identifier
Answer
Answer: c [Reason:] TOS-type of service identifies the type of packets.
3. The TTL field has value 10. How many routers (max) can process this datagram?
a) 11
b) 5
c) 10
d) 1
Answer
Answer: c [Reason:] TTL field is decremented by one each time the datagram is processed by a router.
4. If the value in protocol field is 17, the transport layer protocol used is _____________
a) TCP
b) UDP
c) Either of the mentioned
d) None of the mentioned
Answer
Answer: b [Reason:] For TCP it is 6.
5. The data field can carry which of the following?
a) TCP segemnt
b) UDP segment
c) ICMP messages
d) None of the mentioned
Answer
Answer: c [Reason:] Data field usually has tranaport layer segment, but it can also carry ICMP messages.
6. What should be the flag value to indicate the last fragment?
a) 0
b) 1
c) TTl value
d) None of the mentioned
Answer
Answer: a [Reason:] flag=0 indicates that it is the last fragment.
7. Which of these is not applicable for IP protocol?
a) is connectionless
b) offer reliable service
c) offer unreliable service
d) none of the mentioned
Answer
Answer: b [Reason:] Ip offers unreliable service.
8. Fragmentation has following demerits
a) complicates routers
b) open to DOS attack
c) overlapping of fragments.
d) all of the mentioned
Answer
Answer: d [Reason:] Fragmentation makes the implementation complex and also can create DOS attack.
9. Which field helps to check rearrangement of the fragments?
a) offset
b) flag
c) ttl
d) identifer
Answer
Answer: a [Reason:] Offset field specifies where the fragment fits in the original datagram.
Computer Networks MCQ Set 6
1. The size of IP address in IPv6 is
a) 4bytes
b) 128bits
c) 8bytes
d) 100bits
Answer
Answer: b [Reason:] An IPv6 address is 128 bits long.
2. The header length of an IPv6 datagram is ___________
a) 10bytes
b) 25bytes
c) 30bytes
d) 40bytes
Answer
Answer: d [Reason:] IPv6 datagram has fixed header length of 40bytes, which results is faster processing of the datagram.
3. In the IPv6 header,the traffic class field is similar to which field in the IPv4 header?
a) Fragmentation field
b) Fast-switching
c) ToS field
d) Option field
Answer
Answer: c [Reason:] This field enables to have different types of IP datagram.
4. IPv6 doesnot use _________ type of address
a) Broadcast
b) Multicast
c) Anycast
d) None of the mentioned
Answer
Answer: a [Reason:] Broadcast has been eliminated in IPv6.
5. These are the features present in IPv4 but not in IPv6.
a) Fragmentation
b) Header checksum
c) Options
d) All of the mentioned
Answer
Answer: d [Reason:] All the features are only present in IPv4 and not IPv6.
6. The _________ field determines the lifetime of IPv6 datagram
a) Hop limit
b) TTL
c) Next header
d) None of the mentioned
Answer
Answer: a [Reason:] The Hop limit value is decremented by one by a router when the datagram is forwaded by the router. When the value becomes zero the datagram is discarded.
7. Dual-stack approach refers to
a) Implementing Ipv4 with 2 stacks
b) Implementing Ipv6 with 2 stacks
c) Node has both IPv4 and IPv6 support
d) None of the mentioned
Answer
Answer: c [Reason:] Dual-stack is one of the approach used to support IPv6 in already existing systems.
8. Suppose two IPv6 nodes want to interoperate using IPv6 datagrams but are connected to each other by intervening IPv4 routers. The best solution here is
a) Use dual-stack approach
b) Tunneling
c) No solution
d) Replace the system
Answer
Answer: b [Reason:] The IPv4 routers can form a tuunel.
9. Teredo is an automatic tunneling technique. In each client the obfuscated IPv4 address is represented by bits
a) 96 to 127
b) 0 to 63
c) 80 to 95
d) 64 to 79
Answer
Answer: a [Reason:] Bits 96 to 127 in the datagram represents obfuscated 1Pv4 address.
Computer Networks MCQ Set 6
1. The attackers a network of compromised devices known as
a) Internet
b) Botnet
c) Telnet
d) D-net
Answer
Answer: b [Reason:] None.
2. Which of the following is a form of DoS attack ?
a) Vulnerability attack
b) Bandwidth flooding
c) Connection flooding
d) All of the mentioned
Answer
Answer: d [Reason:] None.
3. The DoS attack is which the attacker establishes a large number of half-open or fully open TCP connections at the target host
a) Vulnerability attack
b) Bandwidth flooding
c) Connection flooding
d) All of the mentioned
Answer
Answer: c [Reason:] None.
4. The DoS attack is which the attacker sends deluge of packets to the targeted host
a) Vulnerability attack
b) Bandwidth flooding
c) Connection flooding
d) All of the mentioned
Answer
Answer: b [Reason:] None.
5. Packet sniffers involve
a) Active receiver
b) Passive receiver
c) Both of the mentioned
d) None of the mentioned
Answer
Answer: b [Reason:] They donot inject packets into the channel.
6. Sniffers can be deployed in
a) Wired environment
b) WiFi
c) Ethernet LAN
d) All of the mentioned
Answer
Answer: d [Reason:] None.
7. Firewalls are often configured to block
a) UDP traffic
b) TCP traffic
c) Both of the mentioned
d) None of the mentioned
Answer
Answer: a [Reason:] None.
8. In a network, If P is the only packet being transmitted and there was no earlier transmission, which of the following delays could be zero
a) Propogation delay
b) Queuing delay
c) Transmission delay
d) Processing delay
Answer
Answer: b [Reason:] None.
Computer Networks MCQ Set 6
1. A local telephone network is an example of a _______ network
a) Packet switched
b) Circuit switched
c) Both of the mentioned
d) None of the mentioned
Answer
Answer: a [Reason:] None.
2. Most packet switches use this principle
a) Stop and wait
b) Store and forward
c) Both of the mentioned
d) None of the mentioned
Answer
Answer: b [Reason:] The packet switch will not transmit the first bit to outbound link until it recieves the entire packet.
3. If there are N routers from source to destination, total end to end delay in sending packet P(L->number of bits in the packet R-> transmission rate)
a) N
b) (N*L)/R
c) (2N*L)/R
d) L/R
Answer
Answer: b [Reason:] None.
4. Method(s) to move data through a network of links and switches
a) Packet switching
b) Circuit switching
c) Line switching
d) Both a and b
Answer
Answer: d [Reason:] None.
5. The resources needed for communication between end systems are reserved for the duration of session between end systems in ________
a) Packet switching
b) Circuit switching
c) Line switching
d) Frequency switching
Answer
Answer: b [Reason:] None.
6. As the resouces are reserved between two communicating end systems in circuit switching, this is achieved
a) authentication
b) guaranteed constant rate
c) reliability
d) store and forward
Answer
Answer: b [Reason:] None.
7. In _________ resources are allocated on demand.
a) packet switching
b) circuit switching
c) line switching
d) frequency switching
Answer
Answer: a [Reason:] In packet switching there is no reservation.
8. Which of the following is an application layer service ?
a) Network virtual terminal
b) File transfer, access, and management
c) Mail service
d) All of the mentioned
Answer
Answer: d [Reason:] None.
