[internet] [internet service] [classification network] [network architecture] [network topology]
§Network architectures is
the way network are designed to communicate.
§Types of network
architecture
§Peer-to-peer (P2P)
§Client-Server
PEER TO PEER
§Definition :
1. A
network model in which all computers can function as
clients or servers as needed, and
there’s no centralized
control over network resources.
2.
Is a simple, inexpensive network that
typically connects
fewer than 10 computers.
PEER TO PEER NETWROK
Most computers function as clients or servers.
Example : A computer can act as a server by sharing a
printer it’s connected to and at the same time act as client by accessing a
file shared by another computer on the network.
PEER TO PEER DIAGRAM
•Advantages
of a peer-to-peer network:
–Less startup cost to setup
the network architecture -
No need for a server.
–Easy to Setup up - An operating system
(such as Windows XP) already in place may only need to be reconfigured for
peer-to-peer operations.
–
•Disadvantages
of a peer-to-peer network:
–Decentralized - No
central repository for files and applications.
–Less Security - Does not provide
the security available on a client/server network
žClient-server network:
Network in which one or more computers act as
a server, and the other computers (clients) on the network request services
from the server
žComputers connected
together to create a network which fall into two categories: clients (workstations) and servers.
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The Client
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The Server
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Computer on a network that requests
resources from the server. Also called a workstation.
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Computer that controls access to the hardware,
software, and other resources on a network, and provides
a centralized storage area for programs, data, and information.
Note: Server can be a mainframe computer used in a
network environment.
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CLIENT DIAGRAM
žServers are special,
powerful computers that provide ‘services’ to the client
computers on the network.
žThese services might
include:
*Providing a central, common file storage area
*Sharing hardware such as printers
*Controlling who can or can’t have access the network
*Sharing Internet connections
An
architecture in which the user's PC (the client) is the requesting
machine, and the server is
the supplying
machine, both of which are
connected via a local area network (LAN) or a wide area network (WAN) such as
the Internet
ADVANTAGE OF CLIENT SERVER..
•Centralized
- Resources and data security are controlled through the server.
•Scalability
- Any or all elements can be replaced individually as needs increase.
•Flexibility -
New technology can be easily integrated into system.
•Interoperability -
All components (client/network/server) work together.
•Accessibility -
Server can be accessed remotely and across multiple platforms.
DISADVANTAGE OF CLIENT SERVER
•Expense
-
Requires initial investment in dedicated server.
•Maintenance
-
Large networks will require a staff to ensure efficient operation.
•Dependence
-
When server goes down, operations will cease across the network
PEER TO PEER VS CLIENT SERVER
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Network
Attribute
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Peer-to-peer
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Client/Server
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Resource access
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Distributed
among many desktop/client computers; makes access to resources more complex
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Centralized on
one or more servers; streamlines access to resources
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Security
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Users control
their own shared resources and might have several sets of ID to access resources
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Security is
managed centrally, and users have a single sets of ID for all shared resources
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Performance
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Desktop OS not
tuned for resources sharing
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Server OS tuned
for resources sharing
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Cost
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Initial costs lower
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Higher up front costs
because of dedicated hardware server OS and on going costs for administrative
support
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