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INTERNET TECHNOLOGY (Network Topology
- Network topology refers to the…
INTERNET TECHNOLOGY
Network Topology
- Network topology refers to the layout of the
computers and devices in a communications
network
-
Star topology
Layout:
• All computers and devices are connected to a
central device (hub or switch).
• Hub or switch are devices that provide a
common central connection point for nodes
on the network.
Data Transfer:
• All data that transfers from one node to
another passes through the hub or switch.
• The hub takes a signal that comes from any
device and passes it to other devices in the
network.
Advantages:
• Failure of one node will not affect the entire
network.
• Devices can be added to or removed from the
network with little or no disruption to the
network.
• Easy to identify problems, making
troubleshooting easier
Disadvantages:
• Failure of hub or switch will shut down the
entire network.
• Requires more cable than the other
topologies.
• More expensive due to the cost of the
hub/switch.
Bus topology
Layout:
• All computers and devices are connected to a
single central cable (called bus).
• The bus is a physical cable that connects the
computers and other devices.
• Terminators are required at both ends of the
backbone cable.
Data Transfer:
• Data transmitted on a bus network travels
along the bus in both directions.
• When a sending device transmits data, the
address of the receiving device is included
with the transmission so that the data is sent
to the appropriate receiving device
If the device address does not match the
intended address for the data, the device
ignores the data.
• If the data address match the device address,
the data is accepted
Advantages:
• Easy and inexpensive to set up.
• Adding and removing nodes can be done
without disturbing the rest of the network.
• Failure of one node does not affect the rest of
the network
Disadvantages:
• Failure of the central cable will shut down the
entire network.
• Only suitable for small size network.
• Data collision may occur because data
transmitted will travel in both directions.
transmission media- any medium to transfer the signals
Eg. cable,radio signal,satellite signal, bluetooth
-
-
Network Architecture
-Network architecture refers to the design of
computers, devices, and media on the
network
• Peer-to-Peer (P2P)
- A network in which each computer (called peer)
have equal capabilities and responsibilities to
share hardware, data or information with other
computers on the network.
• Each computer stores files on its own storage
devices.
• Suitable for small network where high level
security is not necessary.
• Some OS, such as Windows, include a peer-topeer
networking utility that allows users to set up
a peer-to-peer network.
Disadvantages of Peer-to-Peer
• Lack of security control or other management
functions.
• Data recovery or backup is very difficult. Each
computer have to maintain its own backup
system.
Advantages of Peer-to-Peer
• Easy and inexpensive to set up the network.
• More reliable because failure of one peer will
not affect other peers.
• All the peers can share their resources to
others.
• Client/Server
- Efficient for large network which handle sensitive
and confidential data.
• Require a network administrator to manage the
network.
• Examples of client/server systems are:
– automated teller machine (ATM) network
– email service (ex: gmail)
– network printing
– World Wide Web (www)
– Online social network (ex: Facebook)
Advantages of Client/Server
• Centralized control by the server promotes
better security and management of the
network.
• Data backup and recovery is easier since all
data is stored in the server.
Disadvantages of Client/Server
• High cost to set up and maintain the network.
• Less reliable because too dependent on the
server; failure of server will affect the
network.
• Network congestion may occur if too many
clients request services from server at the
same time.
Network- a collection of computers and devices connected together via communication devices and transmission media
communication devices- any hardware that transmits data, instructions and information between sending devices and receiving devices
Eg. network cards, modems, wireless acess point
Advantages of Network
• Share hardware and software
• Transfer fund
• Facilitates communications
• Share data and information
Disadvantages of Network
• Theft of personal information
• Virus threat
- Pornography
• Social disconnect