This document provides an overview of computer networks. It discusses what a network is and some common uses of networks, including sharing resources and communicating. It also describes different types of networks like local area networks (LANs) and wide area networks (WANs). The document outlines how networks are structured, including client/server and peer-to-peer models. It also discusses network topologies, hardware components, common protocols, and the seven-layer OSI model.
2. • Network
• Uses of Network
• Types of Network
• Network Structure
• Network Topologies
• Network Hardware
• Protocols
• OSI Model
CONTENTS
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3. NETWORK
• A group of technologies.
• Two or more computers connected to each other.
• A system of interconnected computers and computerized peripherals such as printers.
• This interconnection among computers facilitates information sharing among them.
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4. USES OF NETWORK
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• A set of technologies.
• Including hardware, software, and media that can be used to connect
computers together.
• Enabling these component to communicate, exchange information, and
share resources in real life.
• It allows many users to access shared data and programs.
• It opens up new ways to communicate, such as email.
5. TYPES OF NETWORK
• Local Area Network (LANs)
• Wide Area Network (WANs)
• Hybrid Networks
• Home Area Networks (HANs)
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6. LANS
• In this type, computers are relatively each
other and are physically connected using
cables, or wireless media.
• It can consist just two or three PCs
connected together to share resources.
• Exist within a building, or even a group of
adjacent buildings.
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7. WANS
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• Two or more LANs connected
together generally across a wide
geographical area.
• Each site in WAN needs resources,
data, and programs locally, but it
also needs to share data with the
other sites.
8. HYBRID NETWORKS
• Between the LAN and WAN structures, we will find hybrid networks such as
campus area networks (CANs) and metropolitan area networks (MANs).
• A new form of network type in emerging called home area networks (HANs).
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HANS
• A network connected within a user’s
home that connects a person’s digital
devices, from multiple computers and
their peripheral devices.
• Including printer,VCRs, DVDs,Video
games, home security system, fax
machines etc.
10. HOW NETWORKS ARE STRUCTURED
• Networks can be categorized by the roles the serves and PCs, play a hierarchical
and security interaction.
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CLIENT/SERVER NETWORK
• In this type, individual computers share the
processing and storage workload with a
central server.
• Client/Server software can be used on LANs
or WANs.
• Common example, a database that can be
accessed by many different computers on
the network, which is stored on the network
server.
11. • Sometimes it is called work-group.
• It refers to the transmission between
two peer computers over a network.
• All nodes on the network have equal
relationships to all others, and all have
similar software that support the
sharing of resources.
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PEER-TO-PEER NETWORK
12. NETWORK TOPOLOGIES
• The logical layout of the cables and devices that connect the
nodes (computer systems) of the network.
• It may define both physical and logical aspect of the network.
• Some topologies are:
Bus Topology
Star Topology
Ring Topology
Mesh Topology
Tree Topology
Hybrid Topology
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13. BUS TOPOLOGY
• It uses one cable all nodes and peripheral
devices are connected in a series to that
cable
• It has a special device, called terminator, is
attached at the cable’s start and end points,
to stop network signals.
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14. STAR TOPOLOGY
• All devices are connected to a device
called a hub and communicate through it
• Some hubs are known as intelligent hubs,
can monitor traffic.
• The benefit is that if a cable fails, only one
node will be brought down.
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15. RING TOPOLOGY
• It connects the network’s nodes in a
circular chain, with each node connected
to the next.
• The last node connects to the first,
completing the ring.
• Each node examines data as it travels
through the ring.
• If any individual connection in the ring is
broken, the entire network is affected.
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16. MESH TOPOLOGY
• A network setup where each
computer and network device is
interconnected with one another.
• It is a topology commonly used
for wireless network.
• A failure of one device does not cause
a break in the network or
transmission of data.
• Building and maintaining the
topology is difficult and time
consuming.
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17. TREE TOPOLOGY
• Also known as Hierarchical Topology.
• This topology imitates as extended Star
topology and inherits properties of Bus
topology.
• It is a special type of structure in which
many connected elements are arranged
like the branches of a tree.
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18. HYBRID TOPOLOGY
• A network structure whose design
contains more than one topology is said
to be hybrid topology.
• Hybrid topology inherits merits and
demerits of all the incorporating
topologies.
• Internet is the best example of largest
Hybrid topology
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19. NETWORK HARDWARE
• Also known as network equipment.
• Electronic devices which are required for communication and interaction
between devices on a computer network.
• Such as hubs, bridges, switches, and routers
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20. HUB
• A hub is basically a multiport repeater.
• An affordable connection point for
different types of devices on a network.
• The most basic networking device that
connects multiple computers or other
network devices together.
• A hub sends data packets (frames) to all
devices on a network.
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21. BRIDGE
• A bridge operates at data link
layer.
• It has a single input and single
output port, thus making it a 2 port
device.
• A device that connects two LANs.
• Connecting two different networks
together and providing
communication between them.
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22. SWITCH
• A switch is a multi port bridge with a
buffer
• A device that learns which machine is
connected to its port by using the IP
addresses.
• Very popular used to connect a LAN.
• Modern switches can even function as
routers.
• Switch can perform error checking
before forwarding data, that makes it
very efficient
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23. ROUTER
• A device like a switch that routes data
packets based on their IP addresses.
• It is mainly a Network Layer device.
• It normally connects LANs and WANs
together.
• Router divide broadcast domains of hosts
connected through it.
•
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24. PROTOCOLS
• A protocol is a standard set of rules that allow electronic devices to communicate
with each other.
• Each protocol has its own method of how data is formatted.
• A set of invisible rules that govern how an internet document gets transmitted to the
screen.
• Examples of Internet computer protocols are:
• http Hypertext Transfer Protocol
• https Hypertext Transfer Protocol Secured
• TCP/IP Transmission Control Protocol/Internet Protocol
• ftp File Transfer Protocol
• UDP User Datagram Protocol
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25. OSI MODEL
• Open System Interconnection.
• OSI is a network model developed by ISO
in 1978 where peer-to-peer
communications are divided into seven
layers.
• Each layer performs a specific task or
tasks and builds upon the preceding layer
until the communications are complete.
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26. LAYERS
• Physical Layer: responsible for the electrical, mechanical, and timing across the link.
• Data Link Layer: responsible for transmitting data across a link.
• Network Layer: responsible for routing information through the network and allowing
systems to communicate.
• Transport Layer: responsible for transferring information between endpoints on the
network and deals with errors, such as lost or duplicate packets.
• Session Layer: responsible for managing a session between two applications.
• Presentation Layer: responsible for the data formatting and display, allowing for
compatibility.
• Application Layer: responsible for user interaction.
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