1.
Define Network?
A network is a set of devices
connected by physical media links. A network is recursively is a connection of
two or more nodes by a physical link or two or more networks connected by one
or more nodes.
2.
What is a Link?
At the lowest level, a
network can consist of two or more computers directly connected by some
physical medium such as coaxial cable or optical fiber. Such a physical medium
is called as Link.
3.
What is a node?
A network can consist of two
or more computers directly connected by some physical medium such as coaxial
cable or optical fiber. Such a physical medium is called as Links and the
computer it connects is called as Nodes.
4.
What is a gateway or Router?
A node that is connected to
two or more networks is commonly called as router or Gateway. It generally
forwards message from one network to another.
5.
What is point-point link?
If the physical links are
limited to a pair of nodes it is said to be point-point link.
6.
What is Multiple Access?
If the physical links are
shared by more than two nodes, it is said to be Multiple Access.
7.
What are the advantages of Distributed Processing?
a. Security/Encapsulation
b. Distributed database
c. Faster Problem solving
d. Security through redundancy
e. Collaborative Processing
b. Distributed database
c. Faster Problem solving
d. Security through redundancy
e. Collaborative Processing
8.
What are the criteria necessary for an effective and efficient network?
a. Performance
It can be measured in many ways, including transmit time and response time. b. Reliability
It is measured by frequency of failure, the time it takes a link to recover from a failure, and the network's robustness.
c. Security
Security issues includes protecting data from unauthorized access and virues.
It can be measured in many ways, including transmit time and response time. b. Reliability
It is measured by frequency of failure, the time it takes a link to recover from a failure, and the network's robustness.
c. Security
Security issues includes protecting data from unauthorized access and virues.
9.
Name the factors that affect the performance of the network?
a. Number of Users
b. Type of transmission medium
c. Hardware
d. Software
b. Type of transmission medium
c. Hardware
d. Software
10.
Name the factors that affect the reliability of the network?
a. Frequency of failure
b. Recovery time of a network after a failure
b. Recovery time of a network after a failure
11.
Name the factors that affect the security of the network?
a. Unauthorized Access
b. Viruses
b. Viruses
12.
What is Protocol?
A protocol is a set of rules
that govern all aspects of information communication.
13.
What are the key elements of protocols?
The key elements of protocols
are
a. Syntax
It refers to the structure or format of the data, that is the order in which they are presented.
b. Semantics
It refers to the meaning of each section of bits.
c. Timing
Timing refers to two characteristics: When data should be sent and how fast they can be sent.
a. Syntax
It refers to the structure or format of the data, that is the order in which they are presented.
b. Semantics
It refers to the meaning of each section of bits.
c. Timing
Timing refers to two characteristics: When data should be sent and how fast they can be sent.
14.
What are the key design issues of a computer Network?
a. Connectivity
b. Cost-effective Resource Sharing
c. Support for common Services
d. Performance
b. Cost-effective Resource Sharing
c. Support for common Services
d. Performance
15.
Define Bandwidth and Latency?
Network performance is
measured in Bandwidth (throughput) and Latency (Delay). Bandwidth of a network
is given by the number of bits that can be transmitted over the network in a
certain period of time. Latency corresponds to how long it t5akes a message to
travel from one end off a network to the other. It is strictly measured in
terms of time.
16.
Define Routing?
The process of determining
systematically hoe to forward messages toward the destination nodes based on
its address is called routing.
17.
What is a peer-peer process?
The processes on each machine
that communicate at a given layer are called peer-peer process.
18.
When a switch is said to be congested?
It is possible that a switch
receives packets faster than the shared link can accommodate and stores in its
memory, for an extended period of time, then the switch will eventually run out
of buffer space, and some packets will have to be dropped and in this state is
said to congested state.
19.
What is semantic gap?
Defining a useful channel
involves both understanding the applications requirements and recognizing the
limitations of the underlying technology. The gap between what applications
expects and what the underlying technology can provide is called semantic gap.
20.
What is Round Trip Time?
The duration of time it takes
to send a message from one end of a network to the other and back, is called
RTT.
21.
Define the terms Unicasting, Multiccasting and Broadcasting?
If the message is sent from a
source to a single destination node, it is called Unicasting.
If the message is sent to some subset of other nodes, it is called Multicasting.
If the message is sent to all the m nodes in the network it is called Broadcasting.
If the message is sent to some subset of other nodes, it is called Multicasting.
If the message is sent to all the m nodes in the network it is called Broadcasting.
22.
What is Multiplexing?
Multiplexing is the set of
techniques that allows the simultaneous transmission of multiple signals across
a single data link.
23.
Name the categories of Multiplexing?
a. Frequency Division
Multiplexing (FDM)
b. Time Division Multiplexing (TDM)
i. Synchronous TDM
ii. ASynchronous TDM Or Statistical TDM.
c. Wave Division Multiplexing (WDM)
b. Time Division Multiplexing (TDM)
i. Synchronous TDM
ii. ASynchronous TDM Or Statistical TDM.
c. Wave Division Multiplexing (WDM)
24.
What is FDM?
FDM is an analog technique
that can be applied when the bandwidth of a link is greater than the combined
bandwidths of the signals to be transmitted.
25.
What is WDM?
WDM is conceptually the same
as FDM, except that the multiplexing and demultiplexing involve light signals
transmitted through fiber optics channel.
26.
What is TDM?
TDM is a digital process that
can be applied when the data rate capacity of the transmission medium is
greater than the data rate required by the sending and receiving devices.
27.
What is Synchronous TDM?
In STDM, the multiplexer
allocates exactly the same time slot to each device at all times, whether or
not a device has anything to transmit.
28.
List the layers of OSI
a. Physical Layer
b. Data Link Layer
c. Network Layer
d. Transport Layer
e. Session Layer
f. Presentation Layer
g. Application Layer
b. Data Link Layer
c. Network Layer
d. Transport Layer
e. Session Layer
f. Presentation Layer
g. Application Layer
29.
Which layers are network support layers?
a. Physical Layer
b. Data link Layer and
c. Network Layers
b. Data link Layer and
c. Network Layers
30.
Which layers are user support layers?
a. Session Layer
b. Presentation Layer and
c. Application Laye
b. Presentation Layer and
c. Application Laye
31.
Which layer links the network support layers and user support layers?
The Transport layer links the
network support layers and user support layers.
32.
What are the concerns of the Physical Layer?
Physical layer coordinates
the functions required to transmit a bit stream over a physical medium.
a. Physical characteristics of interfaces and media
b. Representation of bits
c. Data rate
d. Synchronization of bits
e. Line configuration
f. Physical topology
g. Transmission mode
a. Physical characteristics of interfaces and media
b. Representation of bits
c. Data rate
d. Synchronization of bits
e. Line configuration
f. Physical topology
g. Transmission mode
33.
What are the responsibilities of Data Link Layer?
The Data Link Layer
transforms the physical layer, a raw transmission facility, to a reliable link
and is responsible for node-node delivery.
a. Framing
b. Physical Addressing
c. Flow Control
d. Error Control
e. Access Control
a. Framing
b. Physical Addressing
c. Flow Control
d. Error Control
e. Access Control
34.
What are the responsibilities of Network Layer?
The Network Layer is
responsible for the source-to-destination delivery of packet possibly across
multiple networks (links).
a. Logical Addressing
b. Routing
a. Logical Addressing
b. Routing
35.
What are the responsibilities of Transport Layer?
The Transport Layer is
responsible for source-to-destination delivery of the entire message.
a. Service-point Addressing
b. Segmentation and reassembly
c. Connection Control
d. Flow Control
e. Error Control
a. Service-point Addressing
b. Segmentation and reassembly
c. Connection Control
d. Flow Control
e. Error Control
36.
What are the responsibilities of Session Layer?
The Session layer is the
network dialog Controller. It establishes, maintains and synchronizes the
interaction between the communicating systems.
a. Dialog control
b. Synchronization
a. Dialog control
b. Synchronization
37.
What are the responsibilities of Presentation Layer?
The Presentation layer is
concerned with the syntax and semantics of the information exchanged between
two systems.
a. Translation
b. Encryption
c. Compression
a. Translation
b. Encryption
c. Compression
38.
What are the responsibilities of Application Layer?
The Application Layer enables
the user, whether human or software, to access the network. It provides user
interfaces and support for services such as e-mail, shared database management
and other types of distributed information services.
a. Network virtual Terminal
b. File transfer, access and Management (FTAM)
c. Mail services
d. Directory Services
a. Network virtual Terminal
b. File transfer, access and Management (FTAM)
c. Mail services
d. Directory Services
39.
What are the two classes of hardware building blocks?
Nodes and Links.
40.
What is the different link types used to build a computer network?
a. Cables
b. Leased Lines
c. Last-Mile Links
d. Wireless Links
b. Leased Lines
c. Last-Mile Links
d. Wireless Links
41. What
are the categories of Transmission media?
a. Guided Media
i. Twisted - Pair cable
1. Shielded TP
2. Unshielded TP
ii. Coaxial Cable
iii. Fiber-optic cable
b. Unguided Media
i. Terrestrial microwave
ii. Satellite Communication
i. Twisted - Pair cable
1. Shielded TP
2. Unshielded TP
ii. Coaxial Cable
iii. Fiber-optic cable
b. Unguided Media
i. Terrestrial microwave
ii. Satellite Communication
42.
What are the types of errors?
a. Single-Bit error
In a single-bit error, only one bit in the data unit has changed
b. Burst Error
A Burst error means that two or more bits in the data have changed.
In a single-bit error, only one bit in the data unit has changed
b. Burst Error
A Burst error means that two or more bits in the data have changed.
43.
What is Error Detection? What are its methods?
Data can be corrupted during
transmission. For reliable communication errors must be deducted and Corrected.
Error Detection uses the concept of redundancy, which means adding extra bits
for detecting errors at the destination. The common Error Detection methods are
a. Vertical Redundancy Check (VRC)
b. Longitudinal Redundancy Check (VRC)
c. Cyclic Redundancy Check (VRC)
d. Checksum
a. Vertical Redundancy Check (VRC)
b. Longitudinal Redundancy Check (VRC)
c. Cyclic Redundancy Check (VRC)
d. Checksum
44.
What is Redundancy?
The concept of including
extra information in the transmission solely for the purpose of comparison.
This technique is called redundancy.
45.
What is VRC?
It is the most common and
least expensive mechanism for Error Detection. In VRC, a parity bit is added to
every data unit so that the total number of 1s becomes even for even parity. It
can detect all single-bit errors. It can detect burst errors only if the total
number of errors in each data unit is odd.
46.
What is LRC?
In LRC, a block of bits is
divided into rows and a redundant row of bits is added to the whole block. It
can detect burst errors. If two bits in one data unit are damaged and bits in
exactly the same positions in another data unit are also damaged, the LRC
checker will not detect an error. In LRC a redundant data unit follows n data
units.
47.
What is CRC?
CRC, is the most powerful of
the redundancy checking techniques, is based on binary division.
48.
What is Checksum?
Checksum is used by the
higher layer protocols (TCP/IP) for error detection
49.
List the steps involved in creating the checksum.
a. Divide the data into
sections
b. Add the sections together using 1's complement arithmetic
c. Take the complement of the final sum, this is the checksum.
b. Add the sections together using 1's complement arithmetic
c. Take the complement of the final sum, this is the checksum.
50.
What are the Data link protocols?
Data link protocols are sets
of specifications used to implement the data link layer. The categories of Data
Link protocols are 1. Asynchronous Protocols
2. Synchronous Protocols
a. Character Oriented Protocols
b. Bit Oriented protocols
2. Synchronous Protocols
a. Character Oriented Protocols
b. Bit Oriented protocols
51.
Compare Error Detection and Error Correction:
The correction of errors is
more difficult than the detection. In error detection, checks only any error
has occurred. In error correction, the exact number of bits that are corrupted
and location in the message are known. The number of the errors and the size of
the message are important factors.
52.
What is Forward Error Correction?
Forward error correction is
the process in which the receiver tries to guess the message by using redundant
bits.
53.
Define Retransmission?
Retransmission is a technique
in which the receiver detects the occurrence of an error and asks the sender to
resend the message. Resending is repeated until a message arrives that the
receiver believes is error-freed.
54.
What are Data Words?
In block coding, we divide
our message into blocks, each of k bits, called datawords. The block coding
process is one-to-one. The same dataword is always encoded as the same
codeword.
55.
What are Code Words?
"r" redundant bits
are added to each block to make the length n = k + r. The resulting n-bit
blocks are called codewords. 2n -
2k codewords that are
not used. These codewords are invalid or illegal.
56.
What is a Linear Block Code?
A linear block code is a code
in which the exclusive OR (addition modulo-2) of two valid codewords creates
another valid codeword.
57.
What are Cyclic Codes?
Cyclic codes are special
linear block codes with one extra property. In a cyclic code, if a codeword is
cyclically shifted (rotated), the result is another codeword.
58.
Define Encoder?
A device or program that uses
predefined algorithms to encode, or compress audio or video data for storage or
transmission use. A circuit that is used to convert between digital video and
analog video.
59.
Define Decoder?
A device or program that
translates encoded data into its original format (e.g. it decodes the data). The
term is often used in reference to MPEG-2 video and sound data, which must be
decoded before it is output.
60.
What is Framing?
Framing in the data link
layer separates a message from one source to a destination, or from other
messages to other destinations, by adding a sender address and a destination
address. The destination address defines where the packet has to go and the
sender address helps the recipient acknowledge the receipt.
61.
What is Fixed Size Framing?
In fixed-size framing, there
is no need for defining the boundaries of the frames. The size itself can be
used as a delimiter.
62.
Define Character Stuffing?
In byte stuffing (or
character stuffing), a special byte is added to the data section of the frame
when there is a character with the same pattern as the flag. The data section
is stuffed with an extra byte. This byte is usually called the escape character
(ESC), which has a predefined bit pattern. Whenever the receiver encounters the
ESC character, it removes it from the data section and treats the next
character as data, not a delimiting flag.
63.
What is Bit Stuffing?
Bit stuffing is the process
of adding one extra 0 whenever five consecutive Is follow a 0 in the data, so
that the receiver does not mistake the pattern 0111110 for a flag.
64.
What is Flow Control?
Flow control refers to a set
of procedures used to restrict the amount of data that the sender can send
before waiting for acknowledgment.
65.
What is Error Control ?
Error control is both error
detection and error correction. It allows the receiver to inform the sender of
any frames lost or damaged in transmission and coordinates the retransmission
of those frames by the sender. In the data link layer, the term error control
refers primarily to methods of error detection and retransmission.
66.
What Automatic Repeat Request (ARQ)?
Error control is both error
detection and error correction. It allows the receiver to inform the sender of
any frames lost or damaged in transmission and coordinates the retransmission
of those frames by the sender. In the data link layer, the term error control
refers primarily to methods of error detection and retransmission. Error
control in the data link layer is often implemented simply: Any time an error
is detected in an exchange, specified frames are retransmitted. This process is
called automatic repeat request (ARQ).
67.
What is Stop-and-Wait Protocol?
In Stop and wait protocol,
sender sends one frame, waits until it receives confirmation from the receiver
(okay to go ahead), and then sends the next frame.
68.
What is Stop-and-Wait Automatic Repeat Request?
Error correction in
Stop-and-Wait ARQ is done by keeping a copy of the sent frame and
retransmitting of the frame when the timer expires.
69.
What is usage of Sequence Number in Relaible Transmission?
The protocol specifies that
frames need to be numbered. This is done by using sequence numbers. A field is
added to the data frame to hold the sequence number of that frame. Since we
want to minimize the frame size, the smallest range that provides unambiguous
communication. The sequence numbers can wrap around.
70.
What is Pipelining ?
In networking and in other
areas, a task is often begun before the previous task has ended. This is known
as pipelining.
71.
What is Sliding Window?
The sliding window is an
abstract concept that defines the range of sequence numbers that is the concern
of the sender and receiver. In other words, he sender and receiver need to deal
with only part of the possible sequence numbers.
72.
What is Piggy Backing?
A technique called
piggybacking is used to improve the efficiency of the bidirectional protocols.
When a frame is carrying data from A to B, it can also carry control
information about arrived (or lost) frames from B; when a frame is carrying
data from B to A, it can also carry control information about the arrived (or
lost) frames from A.
73.
What are the two types of transmission technology available?
(i) Broadcast and (ii)
point-to-point
74.
What is subnet?
A generic term for section of
a large networks usually separated by a bridge or router.
75.
Difference between the communication and transmission.
Transmission is a physical
movement of information and concern issues like bit polarity, synchronisation,
clock etc.
Communication means the
meaning full exchange of information between two communication media.
76.
What are the possible ways of data exchange?
(i) Simplex (ii) Half-duplex
(iii) Full-duplex.
77.
What is SAP?
Series of interface points
that allow other computers to communicate with the other layers of network
protocol stack.
78.
What do you meant by "triple X" in Networks?
The function of PAD (Packet
Assembler Disassembler) is described in a document known as X.3. The standard
protocol has been defined between the terminal and the PAD, called X.28; another
standard protocol exists between hte PAD and the network, called X.29.
Together, these three recommendations are often called "triple X".
79.
What is frame relay, in which layer it comes?
Frame relay is a packet
switching technology. It will operate in the data link layer.
80.
What is terminal emulation, in which layer it comes?
Telnet is also called as
terminal emulation. It belongs to application layer.
81.
What is Beaconing?
The process that allows a
network to self-repair networks problems. The stations on the network notify
the other stations on the ring when they are not receiving the transmissions.
Beaconing is used in Token ring and FDDI networks.
82.
What is redirector?
Redirector is software that
intercepts file or prints I/O requests and translates them into network
requests. This comes under presentation layer.
83.
What is NETBIOS and NETBEUI?
NETBIOS is a programming
interface that allows I/O requests to be sent to and received from a remote
computer and it hides the networking hardware from applications.
NETBEUI is NetBIOS extended
user interface. A transport protocol designed by microsoft and IBM for the use
on small subnets.
84.
What is RAID?
A method for providing fault
tolerance by using multiple hard disk drives.
85.
What is passive topology?
When the computers on the
network simply listen and receive the signal, they are referred to as passive
because they don't amplify the signal in any way. Example for passive topology
-linear bus.
86.
What is Brouter?
Hybrid devices that combine
the features of both bridges and routers.
87.
What is cladding?
A layer of a glass
surrounding the center fiber of glass inside a fiber-optic cable.
88.
What is point-to-point protocol?
A communications protocol
used to connect computers to remote networking services including Internet
service providers.
89.
How Gateway is different from Routers?
A gateway operates at the
upper levels of the OSI model and translates information between two completely
different network architectures or data formats.
90.
What is attenuation?
The degeneration of a signal
over distance on a network cable is called attenuation.
91.
What is MAC address?
The address for a
device as it is identified at the Media Access Control (MAC) layer in the
network architecture. MAC address is usually stored in ROM on the network
adapter card and is unique.
92.
Difference between bit rate and baud rate.
Bit rate is the
number of bits transmitted during one second whereas baud rate refers to the
number of signal units per second that are required to represent those
bits.
baud rate = (bit rate / N)
where N is no-of-bits represented by each signal shift.
baud rate = (bit rate / N)
where N is no-of-bits represented by each signal shift.
93.
What is Bandwidth?
Every line has an
upper limit and a lower limit on the frequency of signals it can carry. This
limited range is called the bandwidth.
94.
What are the types of Transmission media?
Signals are usually
transmitted over some transmission media that are broadly classified in to two
categories.
a.) Guided
Media: These are those that provide a conduit from one device to another
that include twisted-pair, coaxial cable and fiber-optic cable. A signal
traveling along any of these media is directed and is contained by the physical
limits of the medium. Twisted-pair and coaxial cable use metallic that accept
and transport signals in the form of electrical current. Optical fiber is a
glass or plastic cable that accepts and transports signals in the form of
light.
b.) Unguided
Media: This is the wireless media that transport electromagnetic waves
without using a physical conductor. Signals are broadcast either through air.
This is done through radio communication, satellite communication and cellular
telephony.
95.
What is Project 802?
It is a project
started by IEEE to set standards to enable intercommunication between equipment
from a variety of manufacturers. It is a way for specifying functions of the
physical layer, the data link layer and to some extent the network layer to
allow for interconnectivity of major LAN protocols.
It consists of the following:
1.
802.1 is an internetworking standard
for compatibility of different LANs and MANs across protocols.
2.
802.2 Logical link control (LLC) is
the upper sublayer of the data link layer which is non-architecture-specific,
that is remains the same for all IEEE-defined LANs.
3.
Media access control (MAC) is the
lower sublayer of the data link layer that contains some distinct modules each
carrying proprietary information specific to the LAN product being used. The
modules are Ethernet LAN (802.3), Token ring LAN (802.4), Token bus LAN
(802.5).
4.
802.6 is distributed queue dual bus
(DQDB) designed to be used in MANs.
96.
What is Protocol Data Unit?
The data unit in
the LLC level is called the protocol data unit (PDU). The PDU contains of four
fields a destination service access point (DSAP), a source service access point
(SSAP), a control field and an information field. DSAP, SSAP are addresses used
by the LLC to identify the protocol stacks on the receiving and sending
machines that are generating and using the data. The control field specifies
whether the PDU frame is a information frame (I - frame) or a supervisory frame
(S - frame) or a unnumbered frame (U - frame).
97.
What are the different type of networking / internetworking devices?
1.
Repeater: Also called a regenerator, it is an electronic
device that operates only at physical layer. It receives the signal in the
network before it becomes weak, regenerates the original bit pattern and puts
the refreshed copy back in to the link.
2.
Bridges: These operate both in the physical and data link
layers of LANs of same type. They divide a larger network in to smaller
segments. They contain logic that allow them to keep the traffic for each
segment separate and thus are repeaters that relay a frame only the side of the
segment containing the intended recipent and control congestion.
3.
Routers: They relay packets among multiple interconnected
networks (i.e. LANs of different type). They operate in the physical, data link
and network layers. They contain software that enable them to determine which
of the several possible paths is the best for a particular transmission.
4.
Gateways: They relay packets among networks that have
different protocols (e.g. between a LAN and a WAN). They accept a packet
formatted for one protocol and convert it to a packet formatted for another
protocol before forwarding it. They operate in all seven layers of the OSI
model.
98.
What is ICMP?
ICMP is Internet
Control Message Protocol, a network layer protocol of the TCP/IP suite used by
hosts and gateways to send notification of datagram problems back to the
sender. It uses the echo test / reply to test whether a destination is
reachable and responding. It also handles both control and error messages.
99.
What are the data units at different layers of the TCP / IP protocol suite?
The data unit
created at the application layer is called a message, at the transport layer
the data unit created is called either a segment or an user datagram, at the
network layer the data unit created is called the datagram, at the data link
layer the datagram is encapsulated in to a frame and finally transmitted as
signals along the transmission media.
100.
What is difference between ARP and RARP?
The address
resolution protocol (ARP) is used to associate the 32 bit IP address with the 48
bit physical address, used by a host or a router to find the physical address
of another host on its network by sending a ARP query packet that includes the
IP address of the receiver.
The reverse address
resolution protocol (RARP) allows a host to discover its Internet address when
it knows only its physical address.
101.
What is the minimum and maximum length of the header in the TCP segment and IP
datagram?
The header should
have a minimum length of 20 bytes and can have a maximum length of 60 bytes.
102.
What is the range of addresses in the classes of internet addresses?
Class A -
0.0.0.0 - 127.255.255.255
Class B - 128.0.0.0 - 191.255.255.255
Class C - 192.0.0.0 - 223.255.255.255
Class D - 224.0.0.0 - 239.255.255.255
Class E - 240.0.0.0 - 247.255.255.255
Class B - 128.0.0.0 - 191.255.255.255
Class C - 192.0.0.0 - 223.255.255.255
Class D - 224.0.0.0 - 239.255.255.255
Class E - 240.0.0.0 - 247.255.255.255
103.
What is the difference between TFTP and FTP application layer protocols?
The Trivial File
Transfer Protocol (TFTP) allows a local host to obtain files from a remote host
but does not provide reliability or security. It uses the fundamental packet
delivery services offered by UDP.
The File Transfer
Protocol (FTP) is the standard mechanism provided by TCP / IP for copying a
file from one host to another. It uses the services offer by TCP and so is
reliable and secure. It establishes two connections (virtual circuits) between
the hosts, one for data transfer and another for control information.
104.
What are major types of networks and explain?
1.
Server-based
network: provide centralized control of
network resources and rely on server computers to provide security and network
administration
2.
Peer-to-peer
network: computers can act as both servers
sharing resources and as clients using the resources.
105.
What are the important topologies for networks?
1.
BUS topology: In this each computer is directly connected to
primary network cable in a single line.
Advantages: Inexpensive, easy to install, simple to understand, easy to extend.
Advantages: Inexpensive, easy to install, simple to understand, easy to extend.
2.
STAR topology: In this all computers are connected using a
central hub.
Advantages: Can be inexpensive, easy to install and reconfigure and easy to trouble shoot physical problems.
Advantages: Can be inexpensive, easy to install and reconfigure and easy to trouble shoot physical problems.
3.
RING topology: In this all computers are connected in loop.
Advantages: All computers have equal access to network media, installation can
be simple, and signal does not degrade as much as in other topologies because
each computer regenerates it.
106.
What is mesh network?
A network in which
there are multiple network links between computers to provide multiple paths
for data to travel.
107.
What is difference between baseband and broadband transmission?
In a baseband
transmission, the entire bandwidth of the cable is consumed by a single signal.
In broadband transmission, signals are sent on multiple frequencies, allowing
multiple signals to be sent simultaneously.
108.
Explain 5-4-3 rule?
In a Ethernet
network, between any two points on the network ,there can be no more than five
network segments or four repeaters, and of those five segments only three of
segments can be populated.
109.
What MAU?
In token Ring , hub
is called Multistation Access Unit(MAU).
110.
What is the difference between routable and non- routable protocols?
Routable protocols
can work with a router and can be used to build large networks. Non-Routable
protocols are designed to work on small, local networks and cannot be used with
a router.
111.
Why should you care about the OSI Reference Model?
It provides a
framework for discussing network operations and design.
112.
What is logical link control?
One of two
sublayers of the data link layer of OSI reference model, as defined by the IEEE
802 standard. This sublayer is responsible for maintaining the link between
computers when they are sending data across the physical network connection.
113.
What is virtual channel?
Virtual channel is
normally a connection from one source to one destination, although multicast
connections are also permitted. The other name for virtual channel is virtual
circuit.
114.
What is virtual path?
Along any
transmission path from a given source to a given destination, a group of
virtual circuits can be grouped together into what is called path.
115.
What is packet filter?
Packet filter is a
standard router equipped with some extra functionality. The extra functionality
allows every incoming or outgoing packet to be inspected. Packets meeting some
criterion are forwarded normally. Those that fail the test are dropped.
116.
What is traffic shaping?
One of the main
causes of congestion is that traffic is often busy. If hosts could be made to
transmit at a uniform rate, congestion would be less common. Another open loop
method to help manage congestion is forcing the packet to be transmitted at a
more predictable rate. This is called traffic shaping.
117.
What is multicast routing?
Sending a message
to a group is called multicasting, and its routing algorithm is called
multicast routing.
118.
What is region?
When hierarchical
routing is used, the routers are divided into what we will call regions, with
each router knowing all the details about how to route packets to destinations
within its own region, but knowing nothing about the internal structure of
other regions.
119.
What is silly window syndrome?
It is a problem
that can ruin TCP performance. This problem occurs when data are passed to the
sending TCP entity in large blocks, but an interactive application on the
receiving side reads 1 byte at a time.
120.
What are Digrams and Trigrams?
The most common two
letter combinations are called as digrams. e.g. th, in, er, re and an. The most
common three letter combinations are called as trigrams. e.g. the, ing, and,
and ion.
121.
Expand IDEA.
IDEA stands for
International Data Encryption Algorithm.
122.
What is wide-mouth frog?
Wide-mouth frog is
the simplest known key distribution center (KDC) authentication protocol.
123.
What is Mail Gateway?
It is a system that
performs a protocol translation between different electronic mail delivery
protocols.
124.
What is IGP (Interior Gateway Protocol)?
It is any routing
protocol used within an autonomous system.
125.
What is EGP (Exterior Gateway Protocol)?
It is the protocol
the routers in neighboring autonomous systems use to identify the set of
networks that can be reached within or via each autonomous system.
126.
What is autonomous system?
It is a collection
of routers under the control of a single administrative authority and that uses
a common Interior Gateway Protocol.
127.
What is BGP (Border Gateway Protocol)?
It is a protocol
used to advertise the set of networks that can be reached with in an autonomous
system. BGP enables this information to be shared with the autonomous system.
This is newer than EGP (Exterior Gateway Protocol).
128.
What is Gateway-to-Gateway protocol?
It is a protocol
formerly used to exchange routing information between Internet core routers.
129.
What is NVT (Network Virtual Terminal)?
It is a set of
rules defining a very simple virtual terminal interaction. The NVT is used in
the start of a Telnet session.
130.
What is a Multi-homed Host?
It is a host that
has a multiple network interfaces and that requires multiple IP addresses is
called as a Multi-homed Host.
131.
What is Kerberos?
It is an
authentication service developed at the Massachusetts Institute of Technology.
Kerberos uses encryption to prevent intruders from discovering passwords and
gaining unauthorized access to files.
132.
What is OSPF?
It is an Internet
routing protocol that scales well, can route traffic along multiple paths, and
uses knowledge of an Internet's topology to make accurate routing decisions.
133.
What is Proxy ARP?
It is using a
router to answer ARP requests. This will be done when the originating host
believes that a destination is local, when in fact is lies beyond router.
134.
What is SLIP (Serial Line Interface Protocol)?
It is a very simple
protocol used for transmission of IP datagrams across a serial line.
135.
What is RIP (Routing Information Protocol)?
It is a simple
protocol used to exchange information between the routers.
136.
What is source route?
It is a sequence of
IP addresses identifying the route a datagram must follow. A source route may
optionally be included in an IP datagram header.
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