3.1.2 Network Architecture
Learning
Outcomes :
Explain
types of network architecture.
§Peer-to-peer
§Client-Server
Network Architecture
Network architectures is the way
network are designed to communicate.
Types of network architecture
- -Peer-to-peer
(P2P)
- Client-Server
Peer to Peer
(p2p)
Client -Server
§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.
ž
- @Most computers function as clients or
servers.
ž
@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
•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
|
|
@Network in which one or more computers
act as a server, and the other computers (clients) on the network request
services from the server.
ž@Computers connected together to create a
network which fall into two categories: clients
(workstations) and servers.
|
The Client
|
The Server
|
|
Computer on a
network that requests resources from the server. Also called a workstation.
|
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.
|
|
| Client-Server network diagram |
Servers
žServers are special, powerful computers
that provide ‘services’ to the client computers on the network.
ž
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
žAn 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.
|
Advantages of a 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.
|
|
Disadvantages of a 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
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|
Peer-to-peer VS Client/Server
Network
|
|
Network Attribute
|
Peer-to-peer
|
Client/Server
|
|
Resource access
|
Distributed among many desktop/client computers;
makes access to resources more complex
|
Centralized on one or more servers; streamlines
access to resources
|
|
Security
|
Users control their own shared resources and might have several sets of ID to access resources
|
Security is managed centrally, and users have a
single sets of ID for all shared resources
|
|
Performance
|
Desktop OS not tuned for resources sharing
|
Server OS tuned for resources sharing
|
|
Cost
|
Initial costs
lower
|
Higher up
front costs because of dedicated hardware server OS and on going costs for
administrative support
|
Peer to Peer (p2p) VS Client-Server
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